tricky or poorly written sample exam problem?

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Predgw

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I took Mike's Civil PE Guide morning exam this past weekend. Compared to the Gowami and Lindberg exams, this was a walk in the park. I believe I have read that aside from the NCEES sample exam, Mike's exam guide is really close to what I will see. You all agree? I scored 34 out of 40. The exam was useful because it exposed a few areas of weakness I have since addressed.

Next question. One of the sample questions showed the dimensions for a headwall with flared wingwalls. I will not bother providing the dimesions because it is not relevant for the question( the math was easy). The headwall is for a 36" diameter pipe. The question ask; How much plywood should the contractor purchase assuming 10% waste. This was obviously super easy and took less than 2 minutes. However, my answer did not match up. Because; 1. Mike forgot to add the end of the wingwalls in ( they need to be formed), 2. Also he subtracted out the area of the pipe.

Remember, the question ask how much plywood should be purchased. You can't purchase a piece of plywood with the hole for the pipe removed. I feel like this was a badly written question. My question for all you would be, will the exam have questions that are written in a poor of confusing manner? The fact that he forget to figure for the end of the wingalls makes me think the question would be tossed anyway.

Thanks.

 
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Exam questions are very straightforward. It is not NCEES's goal to "trick" or confuse the examinees. In this case, it appears that Mike's sample exam solution may be flawed.

When I studied these types of questions, I calculated formwork square footage based on the minimum amount of forms needed to build the concrete walls (top of forms = top of wall, subtract out obstructions, etc). However, if the question is asking how much plywood is necessary to build the forms, you take the formwork SF and add in your 10% waste factor. You would then divide by 32 SF and round up to the next whole number (4'x8' sheet of plywood) if they specifically ask for the number of sheets are needed.

So for this, you would need the SF for the front, back, and 1 end of each wing wall, and the front and back of the headwall itself.

 
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I purchased Mike's Civil PE book and felt this problem was poorly written. When I first looked at the problem, I was in left field when the solution was in right field. The drawing in that problem was not clear. The problem statement said that it was a head wall and when I stared at the drawing I could not see a head wall. I had to trick my mind to picture a form that I could begin solving the problem with. Needless to say, I didn't get the same solution and couldn't figure the solution provided.

The opening in the head wall will require a piece of plywood to be included in the material estimate, a hole has to be cut out of something to be used for the form. I don't remember the solution off hand but I decided to skip this particular problem and move on.

Problems of this nature are better defined in other practice exams and will not be confusing.

 
You can build forms in a way to minimize the cutout section which is why you don't automatically assume you start with a full sheet and cut a hole in it. Anything else that needs to be cut would be included within the 10% waste factor.

 
Maybe with straight cuts, but not a circle. In addition the author subtracted the pipe twice. You actually need a full piece on the front face of the head wall, so the pipe cutout only happens once.

 
I took Mike's Civil PE Guide morning exam this past weekend. Compared to the Gowami and Lindberg exams, this was a walk in the park. I believe I have read that aside from the NCEES sample exam, Mike's exam guide is really close to what I will see. You all agree? I scored 34 out of 40. The exam was useful because it exposed a few areas of weakness I have since addressed.

Next question. One of the sample questions showed the dimensions for a headwall with flared wingwalls. I will not bother providing the dimesions because it is not relevant for the question( the math was easy). The headwall is for a 36" diameter pipe. The question ask; How much plywood should the contractor purchase assuming 10% waste. This was obviously super easy and took less than 2 minutes. However, my answer did not match up. Because; 1. Mike forgot to add the end of the wingwalls in ( they need to be formed), 2. Also he subtracted out the area of the pipe.

Remember, the question ask how much plywood should be purchased. You can't purchase a piece of plywood with the hole for the pipe removed. I feel like this was a badly written question. My question for all you would be, will the exam have questions that are written in a poor of confusing manner? The fact that he forget to figure for the end of the wingalls makes me think the question would be tossed anyway.

Thanks.


1.) I think that is fair to say. The NCEES Sample Q&Ss are by far the most accurate (as far as difficulty) but Mike's is close too.

2.) I remember going through this problem with my co-worker. Problem #9, I believe? We found this problem/solution to be jacked up, as you did. First of all, it's a wingwall, not a headwall, right? Second, I do remember the solution forgetting to include certain areas - it was probably the ends as you said.

The exam will be straight forward and not trick you other than offer you the common "trap" answers obtained from common mistakes. Also, I think you'll find when it is a problem like this, that there is often enough of a difference between answer choices that even if you are undecided on whether or not to include a certain area in the form calculation (say, the inside diameter of the hole), you'll still typically be able to pick the best answer.

 
Maybe with straight cuts, but not a circle. In addition the author subtracted the pipe twice. You actually need a full piece on the front face of the head wall, so the pipe cutout only happens once.
Pipe goes through the wall. You can't form one side because you're going around the pipe. You don't "need" to form the other side because of the hole. Hence, you subtract it twice.

You have to realize there is a certain amount of theoretical calculations needed. Logistically, I don't disagree with you. In the real world, they would do it the way you described. However for estimating purposes, you subtract the area of the pipe and just simply cover it with a "waste factor".

I have seen estimates done by consultants that look at total lineal feet of 2x4's and 2x6's when doing take-offs for home construction (wall & ceiling framing), and just divide the total LF by 8 to get the number of studs to order. However, we both know that if you're framing a 7' tall wall (say a basement wall), you can't just cut off that 1' section and use it somewhere else.

These problems want you to think like an estimator, not a foreman.

 
Problems on the exam won't be vauge. What you do have to look out for is units. There are many problems where the units in the answers are different than what's presented in the question.

 
I should add I thought the book was great overall. The way he explains the answers and then makes suggestions for tabs is helpful.

 
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