# ERRATA - Goswami's Practice Exams (New)

### #1

Posted 11 March 2012 - 06:59 PM

1. An idiot who is taking too long to complete most of these problems.

or

2. The text was poorly written by someone (or people) who did not read the NCEES syllabus and have no concept of what an average 6 minute problem looks like.

So the worry is I may have wasted the equaivalent of 2 to 3 days and money on this text. In short most problems take too long, some are unrelated to the exam (i.e. traffic studies for the AM?), others require obscure equations (i.e. you would probably need the Green Book, etc..., and I'm not a transpo person, to solve.)

There are some good problems in here for sure, but too many take too long. They sort of remind me of the 6 - minute solutions texts and the CERM Practice Problems by Lindeburg. The main difference being those problems are written clearly overall. Anyway, here is what I found so far.

ERRATA

Page 195, Problem 36. Should be 243% increase. (not 143%). Unless I'm mistaken.

Page 37, Problem 120. A lousy question - finding the general relationship for critical velocity/depth for a triangular section. I would like to see if most Civil Hydraulic Professors can solve this inside of 6 minutes? I post this as an Errata because it should be left out of the question set. Maybe a good question for the PM exam, but not AM. Again, 6 minutes.

Page 212, Problem 123. I get V = 6.18 ft/sec. I think Goswami's answer (7.15) works too. Might be a bad coincidence of two intersecting solutions.

Page 40, Problem 126. Did the Author take time to read the NCEES Breadth syllabus for Transportation? Nowhere do I see traffic counts, studies, of any kind. Therefore, this should be removed from the AM and placed in the Transpo PM problem set.

Page 42, Problem 132. See previous statement. Wasted ink.

Page 46, Problem 140. Poorly written. Not clear what we are asked to find: net cost of what? Crashing Schedule option vs. Normal Schedulle?

Again, I have only gone through the AM (#1 and #2) and Construction PM Exams so those venturing further will no doubt uncover more frustration.

thanks,

Jason

### #2

Posted 13 March 2012 - 07:48 PM

In the question 102 diagram, the elevation text overlaps with the tank diagrams

In question 103, remove the "-" before 1.7 inches

In question 112, remove the open parenthesis before A, B, C and D

In the question 123 diagram, change 4 tons to 24 tons

In the question 129 answers A and B, add commas to 2,600 and 3,500

In question 130, add "minimum" after "ladders" in the question

In question 137, indicate the units for the answer choices (inches)

In question 137, correct the spelling of patters to patterns

In solution 101, change 12 <dot> 69 to 12.69. In solution 103, change 1 <dot> 7 to 1.7 and 185 <dot> 5 to 185.5. In solution 106, change 117 <dot> 4 to 117.4. Etc., etc (There are many other instances on other pages too)

In solution 104, change the exponent "<delta>/3" to "8/3". Also, shouldn't the solution specify if n=nf or if n does not = nf for the d/D?

In solution 106, change the first gamma to gamma <sub> d

In solution 107, it appears that c = 1200. What is c and how is it calculated?

In solution 114, what AASHTO Table is being referred to? (Exh 3-2, pg 115 AASHTO does not include 5%)

In solution 118, a quicker method to calc BODu might be to use BODu ~=1.463 x BOD5

In solution 119, change C<sub>z to C<sub>c.

In solution 122, add a comma after "lb" and before "V", first line

**Edited by ptatohed, 13 March 2012 - 07:51 PM.**

### #3

Posted 15 March 2012 - 01:13 PM

I purchased this text about 1 month ago with high hopes. I am not impressed. After going over both AM exams and the Construction PM exam, I am either

1. An idiot who is taking too long to complete most of these problems.

or

2. The text was poorly written by someone (or people) who did not read the NCEES syllabus and have no concept of what an average 6 minute problem looks like.

So the worry is I may have wasted the equaivalent of 2 to 3 days and money on this text. In short most problems take too long, some are unrelated to the exam (i.e. traffic studies for the AM?), others require obscure equations (i.e. you would probably need the Green Book, etc..., and I'm not a transpo person, to solve.)

There are some good problems in here for sure, but too many take too long. They sort of remind me of the 6 - minute solutions texts and the CERM Practice Problems by Lindeburg. The main difference being those problems are written clearly overall. Anyway, here is what I found so far.

ERRATA

Page 195, Problem 36. Should be 243% increase. (not 143%). Unless I'm mistaken.

Page 37, Problem 120. A lousy question - finding the general relationship for critical velocity/depth for a triangular section. I would like to see if most Civil Hydraulic Professors can solve this inside of 6 minutes? I post this as an Errata because it should be left out of the question set. Maybe a good question for the PM exam, but not AM. Again, 6 minutes.

Page 212, Problem 123. I get V = 6.18 ft/sec. I think Goswami's answer (7.15) works too. Might be a bad coincidence of two intersecting solutions.

Page 40, Problem 126. Did the Author take time to read the NCEES Breadth syllabus for Transportation? Nowhere do I see traffic counts, studies, of any kind. Therefore, this should be removed from the AM and placed in the Transpo PM problem set.

Page 42, Problem 132. See previous statement. Wasted ink.

Page 46, Problem 140. Poorly written. Not clear what we are asked to find: net cost of what? Crashing Schedule option vs. Normal Schedulle?

Again, I have only gone through the AM (#1 and #2) and Construction PM Exams so those venturing further will no doubt uncover more frustration.

thanks,

Jason

I've only done 3/4 of the questions of the AM #1 and found a few errors along the way, I'm waiting to hear back from Professor but I have to agree that some of these questions seem way more complicated than I would expect. Also it's not clear on some of his solutions where he's getting some of his values.

I know the CERM questions are harder than the actual exam questions, but any feedback about this exam book versus the actual questions? I'm confident in structural (my discipline) but after donig some of these water/environment questions in the morning #1, i feel like a dope.

### #4

Posted 15 March 2012 - 06:23 PM

Page 37, Problem 120. A lousy question - finding the general relationship for critical velocity/depth for a triangular section. I would like to see if most Civil Hydraulic Professors can solve this inside of 6 minutes? I post this as an Errata because it should be left out of the question set. Maybe a good question for the PM exam, but not AM. Again, 6 minutes.

The equation to solve this is given on page 513 of his book. I don't know if you own his book or not so this may not help.

### #5

Posted 15 March 2012 - 06:24 PM

### #6

Posted 15 March 2012 - 07:54 PM

I think he asks for VDS on 122 but solves for VSS in the solution. I emailed him to see if I'm correct or if I'm looking at this wrong.

I emailed him and, once again, I am an idiot!

### #7

Posted 19 March 2012 - 03:06 AM

Page 37, Problem 120. A lousy question - finding the general relationship for critical velocity/depth for a triangular section. I would like to see if most Civil Hydraulic Professors can solve this inside of 6 minutes? I post this as an Errata because it should be left out of the question set. Maybe a good question for the PM exam, but not AM. Again, 6 minutes.

The equation to solve this is given on page 513 of his book. I don't know if you own his book or not so this may not help.

Benny,

My point is the problem is way over 6 minutes. His problems are based upon the structure of his book, not the structure of the NCEES syllabus. Assume you do not have his book (I do) and you encounter that problem on the exam. What to do? Can't look it up in CERM, it's not there. So you need to derive it. And fast. Not a 6 minute problem, more like a 10-15 minute, unless your a Water Resources pro (I'm not).

Having said that I do like his book. It's a perfect companion to the CERM. If I can't find something in the CERM, or just need clarity, I reach for Goswami's text. It's very good. I just don't care for his sample exams overall. Again, there are very good questions in there, it's just that most take way beyond 6 minutes.

thanks,

Jason

### #8

Posted 19 March 2012 - 09:23 AM

Page 37, Problem 120. A lousy question - finding the general relationship for critical velocity/depth for a triangular section. I would like to see if most Civil Hydraulic Professors can solve this inside of 6 minutes? I post this as an Errata because it should be left out of the question set. Maybe a good question for the PM exam, but not AM. Again, 6 minutes.

The equation to solve this is given on page 513 of his book. I don't know if you own his book or not so this may not help.

Benny,

My point is the problem is way over 6 minutes. His problems are based upon the structure of his book, not the structure of the NCEES syllabus. Assume you do not have his book (I do) and you encounter that problem on the exam. What to do? Can't look it up in CERM, it's not there. So you need to derive it. And fast. Not a 6 minute problem, more like a 10-15 minute, unless your a Water Resources pro (I'm not).

Having said that I do like his book. It's a perfect companion to the CERM. If I can't find something in the CERM, or just need clarity, I reach for Goswami's text. It's very good. I just don't care for his sample exams overall. Again, there are very good questions in there, it's just that most take way beyond 6 minutes.

thanks,

Jason

I don't have the Goswami practice problem book because I bought his practice exams from him when they used to be e-mailed PDFs but I think you guys are talking about this problem, right? Practice exam No. 2, #120. A triangular channel with 1V:3H sides, Q=10 CFS, S = 0.5%, n = .015, what is the critical velocity?

Yeah, the CERM doesn't have the neat formula that the AI1 has on page 513 (303.42) but this is how I'd solve it using the CERM (I have the 10th edition CERM so my page numbers may not match other editions). Not sure if this would take less than 6 minutes or not in the heat of battle.

Step 1: CERM Appendix 19.E (10th edition page A-41): Q = K (1/n) d^(8/3) S^.5. Rearrange, solve for d. d = [Q (1/K) n (1/(S^.5))]^(3/8). From the table, K = 2.71 and therefore

**d = 0.9122 ft**

Step 2: CERM Table 19.2 (10th edition page 19-3): A(triangle) = d^2 / tan < theta > (or, A(triangle) = m d^2). Theta = 18.4 degrees and therefore

**A = 2.50 ft^2**

Step 3: CERM equation 19.1 (10th edition page 19-2): Q = V A. Rearrange, solve for V. V = Q / A.

**V = 4.0 ft/sec**

I get 4.0 and Goswami gets 3.9.

Do you guys see any errors in my process?

**Edited by ptatohed, 19 March 2012 - 09:28 AM.**

### #9

Posted 19 March 2012 - 08:13 PM

Thanks for sharing.

Jason

### #10

Posted 20 March 2012 - 04:18 AM

### #11

Posted 20 March 2012 - 05:28 PM

Page 195, Problem 36. Should be 243% increase. (not 143%). Unless I'm mistaken.

**You are mistaken. If the before and after values had been equal and the ratio had been 1.00, would the % increase be 100%?**

Page 37, Problem 120. A lousy question - finding the general relationship for critical velocity/depth for a triangular section. I would like to see if most Civil Hydraulic Professors can solve this inside of 6 minutes? I post this as an Errata because it should be left out of the question set. Maybe a good question for the PM exam, but not AM. Again, 6 minutes.

**I believe ptatohed has answered this.**

Page 212, Problem 123. I get V = 6.18 ft/sec. I think Goswami's answer (7.15) works too. Might be a bad coincidence of two intersecting solutions.

**V = 6.18 ft/sec doesn’t fit the equation**

Page 40, Problem 126. Did the Author take time to read the NCEES Breadth syllabus for Transportation? Nowhere do I see traffic counts, studies, of any kind. Therefore, this should be removed from the AM and placed in the Transpo PM problem set.

**Every page of the official syllabus has the following fine print –**

**The knowledge areas specified as examples of kinds of knowledge are not exclusive or exhaustive categories.**

Page 42, Problem 132. See previous statement. Wasted ink.

**See previous statement.**

Page 46, Problem 140. Poorly written. Not clear what we are asked to find: net cost of what? Crashing Schedule option vs. Normal Schedulle?

**Agreed. The language could definitely have been clearer. As solved, the word ‘net’ implies cost + bonus – penalties for crashing.**

### #12

Posted 21 March 2012 - 12:15 AM

AAAARGH!! I'm starting to wonder if I can trust his book at all, and I've been using it instead of the CERM for most of my studying.

### #13

Posted 21 March 2012 - 12:53 AM

problem 508 from transpo. in the solution he uses equation 404.36 from his book with the spiral angle in degrees. in his book it says to use spiral angle in radians with equation 404.36. Which is it?

AAAARGH!! I'm starting to wonder if I can trust his book at all, and I've been using it instead of the CERM for most of my studying.

benny,

I am nearly certain that spiral curves are not on the exam. Don't waste your time studying topics you won't be tested on. I always skipped the spiral stuff (in CERM, in AI1, in Green Book) and never saw it on the Transpo PM (took twice) nor the CA-Survey.

### #14

Posted 21 March 2012 - 01:51 AM

Equation 404.36 gives "k = xproblem 508 from transpo. in the solution he uses equation 404.36 from his book with the spiral angle in degrees. in his book it says to use spiral angle in radians with equation 404.36. Which is it?

AAAARGH!! I'm starting to wonder if I can trust his book at all, and I've been using it instead of the CERM for most of my studying.

_{c}- R

_{c}sin theta

_{s}= L

_{s}(0.5 - q

_{s}

^{2}/60)"

If you use the sin theta

_{s }version, it doesn't matter whether theta is angles or radians as long as your calculator is set to the right mode. If you use the alternate expression, then you theta must be in radians.

### #15

Posted 21 March 2012 - 03:12 PM

### #16

Posted 23 March 2012 - 07:18 PM

### #17

Posted 23 March 2012 - 07:19 PM

### #18

Posted 23 March 2012 - 07:26 PM

### #19

Posted 23 March 2012 - 07:55 PM

### #20

Posted 24 March 2012 - 05:45 PM

thanks,

Jason

### #21

Posted 24 March 2012 - 09:21 PM

### #22

Posted 24 March 2012 - 09:25 PM

### #23

Posted 25 March 2012 - 12:31 AM

Goswami Depth Prob 404 - (Water Resources) - how is it possible to relate concentration of micrograms per liter to a flowrate in cfs - something dosen't seem right here.. shouldn't we be converting MGD to CFS to flow rates to liters per second since the contamination levels are given in micrograms per liter?? The units don't cancel as you have the 3.094x term where 3.094 represents CFS at the plant.

[Q1(cfs) x conc1 (g/L) + Q2(cfs) x conc2 (g/L)]

---------------------------------------------------------- = average conc (g/L)

Q1(cfs) + Q2(cfs)

Units work, what's the problem?

**Edited by civilized_naah, 25 March 2012 - 12:32 AM.**

### #24

Posted 25 March 2012 - 01:15 AM

### #25

Posted 26 March 2012 - 09:30 PM

### #26

Posted 27 March 2012 - 12:50 AM

### #27

Posted 27 March 2012 - 01:41 PM

Where? On which page is the 70 ft used?delta Z for Pump Problem 405 (Depth) on page 106 uses 70' as delta Z - should be 80'

### #28

Posted 28 March 2012 - 01:57 AM

You are not alone (thebettersmith@aol.com) live in MD - we can talk about exam - trepedation (sp) is building but you are not alone.. you sound prepared.. humility is yet the first bud of victory. RudyGood catch. Thanks!

### #29

Posted 28 March 2012 - 02:00 AM

Good catch. Thanks!

### #30

Posted 28 March 2012 - 02:29 AM

Where is the delta Z = 70 ft? Did not see it ...Where? On which page is the 70 ft used?

delta Z for Pump Problem 405 (Depth) on page 106 uses 70' as delta Z - should be 80'

### #31

Posted 28 March 2012 - 07:10 PM

Where is the delta Z = 70 ft? Did not see it ...

Where? On which page is the 70 ft used?

delta Z for Pump Problem 405 (Depth) on page 106 uses 70' as delta Z - should be 80'

^^^

c_n takes this very personally.

### #32

Posted 06 April 2012 - 04:36 AM

### #33

Posted 06 April 2012 - 12:43 PM

### #34

Posted 10 April 2012 - 09:44 PM

ERRATA

Page 195, Problem 36. Should be 243% increase. (not 143%). Unless I'm mistaken.

You are mistaken. If the before and after values had been equal and the ratio had been 1.00, would the % increase be 100%? OK.

Page 37, Problem 120. A lousy question - finding the general relationship for critical velocity/depth for a triangular section. I would like to see if most Civil Hydraulic Professors can solve this inside of 6 minutes? I post this as an Errata because it should be left out of the question set. Maybe a good question for the PM exam, but not AM. Again, 6 minutes.

I believe ptatohed has answered this. I answered back. Move problem to PM Transpo.

Page 212, Problem 123. I get V = 6.18 ft/sec. I think Goswami's answer (7.15) works too. Might be a bad coincidence of two intersecting solutions.V = 6.18 ft/sec doesn’t fit the equation. Depends what version you are reading.

Page 40, Problem 126. Did the Author take time to read the NCEES Breadth syllabus for Transportation? Nowhere do I see traffic counts, studies, of any kind. Therefore, this should be removed from the AM and placed in the Transpo PM problem set.Every page of the official syllabus has the following fine print –The knowledge areas specified as examples of kinds of knowledge are not exclusive or exhaustive categories. Are you a friend of Goswami and/or relative? I don't work on potential. Only the facts are important.If we follow your logic then let's just add specs from the Green Book into the AM and every PM depth even though it's not a listed reference for anyone other than Transportation. In doing so we'll add stuff like traffic counts and studies. Wrong.

Page 42, Problem 132. See previous statement. Wasted ink.See previous statement. See previous statement.

Page 46, Problem 140. Poorly written. Not clear what we are asked to find: net cost of what? Crashing Schedule option vs. Normal Schedulle?Agreed. The language could definitely have been clearer. As solved, the word ‘net’ implies cost + bonus – penalties for crashing.I don't care how he/his graduate student solved it. After reading the problem I immediately discounted it.

### #35

Posted 11 April 2012 - 02:10 PM

### #36

Posted 11 April 2012 - 04:55 PM

### #37

Posted 11 April 2012 - 05:01 PM

### #38

Posted 11 April 2012 - 05:01 PM

### #39

Posted 11 April 2012 - 05:01 PM

### #40

Posted 11 April 2012 - 05:08 PM

I think there were a couple more as well, but the above shows that 10% of the geotech solutions are wrong. This is not helpful at all when trying to prepare for an exam!

### #41

Posted 11 April 2012 - 05:28 PM

There has yet to be ONE legitimate ERROR named in this string

I thought I had a couple of legit errors (yes, many are just formatting/presentation) in post #2, no? But, again, I was using the e-mailed PDF practice exams. Maybe the published book addressed these few errors. I wouldn't worry about the comments here c_n. Everyone is under a lot of stress at this time, a day or two before the exam. After they pass, they'll forget all about any negative comments they might have had and will only have positive comments for this book.

### #42

Posted 11 April 2012 - 06:08 PM

There has yet to be ONE legitimate ERROR named in this string

Wrong. Try reading your own book Dr.

### #43

Posted 11 April 2012 - 06:30 PM

Not one legitimate error? In addition to what's posted above, apparently the following aren't legitamate errors either

- Page 251, Problem 304. Solution gives angle of friction = 0, yet question gives friction angle = 15. I get ka=0.5, not 0.34.
- Page 17, Problem 31. Problem assumes bucket capacity @ loose measure. Only the truck would have loose measure, not bucket. Thus, no. of days = 9.
- Page 322, Problem 616. Total cost is wrong, because truck operational cost is wrong, because total truck hours are wrong. I'll leave it to you to explain why this is not a legimitate error.

Thanks,

Jason

### #44

Posted 11 April 2012 - 06:40 PM

Again, nothing personal against anyone here. I'm sure the Dr. is a great person. But when you charge good money you should produce a good product.

thanks,

Jason

### #45

Posted 12 April 2012 - 02:40 AM

Problem 31. Problem assumes bucket capacity @ loose measure. Only the truck would have loose measure, not bucket. Thus, no. of days = 9.

RESPONSE:

So when soil is dug up and released from confining pressures, there is no bulking?

Problem 140. Not clear what we are asked to find: net cost of what? Crashing Schedule option vs. Normal Schedule?

**RESPONSE:**

**Agreed. The language could definitely have been clearer. As solved, the word ‘net’ implies cost - bonus + penalties for crashing.**

Problem 304. Solution gives angle of friction = 0, yet question gives friction angle = 15. I get Ka=0.5, not 0.34.

**RESPONSE:**

Angle of friction between BACKFILL soil and wall stem is taken to be zero. It is not specified and does NOT have to be the same as the angle of friction between the NATIVE soil and the wall footing, which is given as 20 (not 15). There does not seem to be any error in the value of Ka

Problem 315: Error in calculating depth from bottom 2/3 of pile length to middle of clay layer being compressed, …

**RESPONSE:**

THANK YOU FOR THIS CORRECTION

The thickness that will consolidate is 23.33 ft thick, with center 11.67 ft below point of load transfer. The corrections are:

Delta p = 342.6

P2 = 4697.6

Settlement = 2.6 in

Problem 337- error- shouldn't square y1 and y2 terms in solution,

**RESPONSE:**

WHY NOT?

Problem 339- Shouldn't use Ca for group pile skin friction (just use cohesion, no alpha reduction like with single pile).

**RESPONSE:**

THANK YOU FOR THIS CORRECTION

The diagram for problem 315 should have been used here. The cohesion should be used instead of adhesion.

Problem 616. Total cost is wrong, because truck operational cost is wrong, because total truck hours are wrong.

**RESPONSE:**

THANK YOU FOR THIS CORRECTION

Total truck operating hours = 1134x2.583 = 2929 hrs (was multiplied by just 2 instead of 2.583)

Truck operating cost = 234,330

Total cost = 326,880

Cost per cu yd = 21.79

### #46

Posted 12 April 2012 - 04:23 AM

**RESPONSE:**

WHY NOT?

According to Both VNS Murhthy and Braja Das texts, these values are not squared for a confined aquifer. They are however, squared in the equation for an unconfined aquifer.

Additional error: in problem 318 solution: resultant earth pressure is listed as 35,513- think it should be 41,313. I think this may just be a math error in the solution and the procedure is correct.

Also- problem 307, shouldn't the solution subtract out the depth of material removed for the mat construction when calculation delta P for settlement equation?

I still think there is an error in the solution to 304. Solution states that rankine's active earth pressure coefficient is Ka is .339. If you use rankine's equation modified for the sloping back fill you get Ka =.311, unless I'm mistaken

Thanks for taking the time to respond. Sorry for negative tone but it is frustrating finding errors in solutions when trying to prepare for an exam, I think I have found a total of 6 errors out of 40 problems (with 1 of them maybe being a simple math error). While trying to learn, you may think you have been doing it wrong all along and the solution is correct, or even worse learning something wrong for the first time (like me trying to compute settlement of the pile group). I spent some time comparing some of the errors to other sample problems and solutions to figure out what was correct and incorrect.

My apologies and Thanks again.

### #47

Posted 12 April 2012 - 04:43 AM

I never did understand why in the solution to problem 335 the CSR*effective overburden stress goes in the denominator of the of the FS of equation, yet it goes into the numerator in the 2007 NCEES and 2011 NCEES sample exam. I don't know much about this topic but one must be incorrect.

### #48

Posted 12 April 2012 - 05:38 AM

additionally,

I never did understand why in the solution to problem 335 the CSR*effective overburden stress goes in the denominator of the of the FS of equation, yet it goes into the numerator in the 2007 NCEES and 2011 NCEES sample exam. I don't know much about this topic but one must be incorrect.

I believe in the NCEES question (no. 514 from the 2010 version), the questions states: "maximum allowable cyclic stress ration is 0.29". To me that reads like the cyclic STRENGTH ratio is 0.29. That's why in their solution, they calculate the ULTIMATE shear stress based on this and put it in the numerator of the FS calc. There's nothing wrong with that, except it should not be called the cyclic stress ratio (but they did put the words "maximum allowable" in front of it, so it is kind of OK).

In problem 335, the question states "cyclic stress ration for s design earthquake is 0.21". That means that the actual cyclic shear stress due to this earthquake is to be calculated using the 0.21 value. That's why it belongs in the denominator.

Both are correct.

### #49

Posted 12 April 2012 - 05:49 AM

Are you sure, you are not using the version that uses the drawdown values s1 and s2, instead of the water elevation values y1 and y2?Problem 337- error- shouldn't square y1 and y2 terms in solution,

According to Both VNS Murhthy and Braja Das texts, these values are not squared for a confined aquifer. They are however, squared in the equation for an unconfined aquifer.

### #50

Posted 12 April 2012 - 05:51 AM

I have checked this again with a spreadsheet. Linear interpolation from Table 208.1 in the All in One book had yielded Ka = 0.,339, but the exact value I am getting is Ka = 0.334. I am not getting the 0.311 you mentioned. I will check that spreadsheet again, or do it overI still think there is an error in the solution to 304. Solution states that rankine's active earth pressure coefficient is Ka is .339. If you use rankine's equation modified for the sloping back fill you get Ka =.311, unless I'm mistaken

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