Question about an Answer on the CDL Practice Tests

Hey fellow drivers...I have a question about one of the answers on the CDL practice tests on this site. In a nutshell, I have been tutoring this kid (well...he's 22 yrs. old, but that's a kid to me...lol) and he keeps getting this question wrong on the combo test:

"The air leakage rate on a combination vehicle (engine off, brakes on) should not be more that ____ psi per minute."

A. 2
B. 3
C. 4
D. 2 1/2

According to the answers after he completes the test it is C or 4 psi.

However, on the general knowledge test the same question has an answer of 3 psi. It seems to me the correct answer is 3, is it possible this question has the wrong answer on the combo test?

The kid has been getting 88-94% on all of the practice exams, so I told him not to sweat it too much, but it has been bugging me ever since he emailed about it a couple of days ago. Anyone know what is the correct answer?

Thanks...Chef Brian

 

I thought it was 3 with trailer and 2 without. However, when I went and looked at the gen/know exam I found two different questions that were worded similar and both of them had an answer of 3. To be honest...I cant remember and it's been 3 yrs. since I took the actual exam.

 

Some of the questions are closely worded so he (and I) may have misread them. When I was taking the practice exams looking for the questions he pointed out to me, I noticed that I consistently missed questions involving numbers...like stopping distance @ (X) amount of speed or how many seconds I should be looking ahead at (X) amount of speed. While those are of course important things to know, those answers will vary dependent upon driving conditions and time of day and an experienced driver knows that and drives their rig accordingly.

 

Thanks...to be honest with everyone, I'm beginning to believe that he is missing something in the question as am I. I'm probably missing it because (1) I don't have a hard copy of a CDL manual to look at, and (2) I skimmed over the practice exam (three times looking for the same questions) and probably misinterpreted the wording.

Thanks to all that to the time to respond though...much appreciated!