round off values in PE exam

[visu212]

hello PEs,

Can you tell from your previous experience that Exam answers are usually rounded off? For example the result you calculated is 111 volts but one of answer in multiple choices is 110 Volts?

TIA

 

[MechGuy]

hello PEs,
Can you tell from your previous experience that Exam answers are usually rounded off? For example the result you calculated is 111 volts but one of answer in multiple choices is 110 Volts?

TIA

On many questions on the PE exam, you will find the question states "find the BEST answer" out of the multiple choices. So yes, your calculations could come up with 1.21 Gigawatts but the choices listed are 1.1, 1.2, 1.3 and 1.4 Gigawatts and you need to pick the best answer.

On that note, the question to this particular answer would be "How many Gigawatts does it take in a DeLorean traveling at 85 mph to go back in time 30 years, say from 1985 to 1955 and take your mother to the prom?"

 

[krenim]

On many questions on the PE exam, you will find the question states "find the BEST answer" out of the multiple choices. So yes, your calculations could come up with 1.21 Gigawatts but the choices listed are 1.1, 1.2, 1.3 and 1.4 Gigawatts and you need to pick the best answer.
On that note, the question to this particular answer would be "How many Gigawatts does it take in a DeLorean traveling at 85 mph to go back in time 30 years, say from 1985 to 1955 and take your mother to the prom?"

But only if you pronounce it "Jiggawatts".

 

[FutureCSE]

On many questions on the PE exam, you will find the question states "find the BEST answer" out of the multiple choices. So yes, your calculations could come up with 1.21 Gigawatts but the choices listed are 1.1, 1.2, 1.3 and 1.4 Gigawatts and you need to pick the best answer.
On that note, the question to this particular answer would be "How many Gigawatts does it take in a DeLorean traveling at 85 mph to go back in time 30 years, say from 1985 to 1955 and take your mother to the prom?"

The best answer is 1.3, right? 1.2 ain't gonna cut it.

 

[jeb6294]

The best answer is 1.3, right? 1.2 ain't gonna cut it.

That's exactly right...you have to make sure you read the question closely to see what they're asking for. They may just say "find the answer closest to", in which case you just pick the one that is closest to what you got.

In some cases they may ask something like "what's the minimum size pipe you need to convey a flow of 2cfs at a grade of 0.5%?" Knowing that, if you do the problem correctly, you should come out with an answer of 6.2 inches they will provide possible answers of 4-in, 6-in, 8-in, and 10-in. If you're in a hurry you may fill in the circle for 6-in and move on to the next question thinking you got an easy one right. In reality you just missed an easy one beacause the question is what's the minimum size...according to your solution a 6-in pipe is almost big enough but not quite so the correct answer would have to be 8-inches.

 

[MechGuy]

That's exactly right...you have to make sure you read the question closely to see what they're asking for. They may just say "find the answer closest to", in which case you just pick the one that is closest to what you got.
In some cases they may ask something like "what's the minimum size pipe you need to convey a flow of 2cfs at a grade of 0.5%?" Knowing that, if you do the problem correctly, you should come out with an answer of 6.2 inches they will provide possible answers of 4-in, 6-in, 8-in, and 10-in. If you're in a hurry you may fill in the circle for 6-in and move on to the next question thinking you got an easy one right. In reality you just missed an easy one beacause the question is what's the minimum size...according to your solution a 6-in pipe is almost big enough but not quite so the correct answer would have to be 8-inches.

Right on -- I forgot that particular scenario. Yes some answers might be the closest and others may force you to remember you have to size appropriately.

Thanks for the correction!

 

[IlPadrino]

That's exactly right...you have to make sure you read the question closely to see what they're asking for. They may just say "find the answer closest to", in which case you just pick the one that is closest to what you got.
In some cases they may ask something like "what's the minimum size pipe you need to convey a flow of 2cfs at a grade of 0.5%?" Knowing that, if you do the problem correctly, you should come out with an answer of 6.2 inches they will provide possible answers of 4-in, 6-in, 8-in, and 10-in. If you're in a hurry you may fill in the circle for 6-in and move on to the next question thinking you got an easy one right. In reality you just missed an easy one beacause the question is what's the minimum size...according to your solution a 6-in pipe is almost big enough but not quite so the correct answer would have to be 8-inches.

I think you'll find that usually the answers won't be so close... but this sort of thinking will help you immensely as you'll stop plugging-and-chugging long enough to think "does this make sense?"

Great advice, jeb!

 

[klk]

And I know its been said often, but don't forget to check your units! They don't include units in the answer options. On several questions, I had selected the wrong answer because I hadn't converted it to the units stated in the sample problem. Thankfully, I realized it later when I was checking my work and had the opportunity to change my answers. On the above example, the options would have been 0.5, 0.67, 6, and 8, and they could have asked for the answer in feet instead of inches.

 

[IlPadrino]

And I know its been said often, but don't forget to check your units! They don't include units in the answer options.

Is that true today? I remember answers having units...

 

[jroyce]

Is that true today? I remember answers having units...

In the Mechanical test some answers had units and other questions had the units listed in the question (i.e. what is the flow in gpm?) and then the answers were only numbers. I guess this would be to make sure that all your conversions are correct. I think units are still important but maybe not as important as they used to be. You just have to be mindful of the units and maek sure that you are solving for what is asked.

 

[IlPadrino]

You just have to be mindful of the units and maek sure that you are solving for what is asked.

There's no doubt about that! Failing to properly convert units can make the difference between pass and fail.