CEPP Ch 74 Problem 2g

[Jennifer Price]

CEPP Ch 74 Problem 2g asks what the uphill percent time following is? The solution to the problem references HCM Exhibit 20-21 for the coefficient values of a and b. But when I compared what the CEPP put down for the coefficients a and b, they didn't match anything the HCM said. This also held true when I needed to find the no-passing adjustment factor (fnp) (Exhibit 20-20). The factor in the solution did not match the factor in the HCM.

Am I missing something completely obvious?

 

[rktatum24]

I worked this problem when I was studying as well, and I found that there are errors in the solutions in Problem 74-2. I don't have my books with me anymore (I let a friend borrow them after I passed), but I remember that the coefficients were used incorrectly in the problem. I also remember that when calculating ATS that they used the equation incorrectly because they placed a plus sign in the equation where a minus sign should have been (This was the 9th edition CEPP book). It drove me crazy for a couple of days because I didn't realize what I was doing wrong. Be sure to look over the solutions in the book and find the errors because there are some in that problem.

 

[Jennifer Price]

Be sure to look over the solutions in the book and find the errors because there are some in that problem.

I worked through the 6 minute Transportation book this weekend (it was a loonnnggg weekend) but found another huge mistake! Problem 31 in the 6 minute book is identical (as far as I could tell) to CEPP Ch 74 Problem 1 - so I was thinking to myself that it would be one less problem that I had to work. But when I started comparing the solutions to both problems, I found that the CEPP solution used an incorrect conversion factor (that I didn't catch - shame on me) which made the answer completely different. I was a bit irritated about it but at the same time glad that I caught it before I used the incorrect conversion during the test.