Choosing answers

[ktulu]

While working problems from the "the other board" Civil PE Sample Exam, when they choose an answer, they always choose the lower possible answer.

For example, the calculated answer was 184 kN. Two answers were 180 kN & 190 kN. "the other board" chose 180 kN. Of course, the question had the "most nearly" phrase in it, but I have read advice saying that you should always choose the higher of your possible answers, when encountered in this situation....I would have chosen 190 kN and would have been wrong.

Any thoughts on this???

 

[EdinNO]

Just an off the cuff opinion, but I think that the most correct answer that at least satisfies the problem statement would be the best choice.

Ie, if the calc'd load were 184kN and you were ultimately meant to calculate the factor of safety on a bridge, you might more conservatively choose the load to be the 190kN over the 180. Slightly too strong a bridge is better then slightly too weak.

I think NCEES uses this type of logic or trickery.

Ed

 

[Guest]

Totally agree with Ed on this one. I think you need to take into account the 'qualifier' for what you are being asked, like:

• smallest diameter pipe
  
• greatest maximum load
  
• minimum cross-sectional area
  

These terms give you an idea as to whether you should round up or down - same considerations when selecting design elements based on a specification.

:17:

JR

 

[ktulu]

I agree with you guys after looking at what was being asked. The problem asked to find the ultimate pullout load capacity of a single concrete pile......the 190 kN answer does not satisfy the requirement, therefore the 180 kN answer should be chosen....

Again, goes to show how a little discussion can go a long ways....

Thanks, guys..

ktulu