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Work Rate Problem - 2

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Work Rate Problem - 2

by saadishah » Tue Sep 27, 2016 10:42 am
Adam and Brianna plan to install a new tile floor in a classroom. Adam works at a constant rate of 50 tiles per hour, and Brianna works at a constant rate of 55 tiles per hour. If the new floor consists of exactly 1400 tiles, how long will it take Adam and Brianna working together to complete the classroom floor?

A. 26 hrs. 44 mins.
B. 26 hrs. 40 mins.
C. 13 hrs. 20 mins.
D. 13 hrs. 18 mins.
E. 12 hrs. 45 mins.

The solution to this problem came so easy that I feel like I am making some mistake :-)

Here is how I have solved it:

Combined Rate of A + B = 50 + 55 = 105
Total tiles = 1400
Time needed to finish 1400 tiles = 1400/105 = 13 hours and 35/105 minutes which simplifies to be 13 hours 20 minutes.

So option C.
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by Brent@GMATPrepNow » Tue Sep 27, 2016 12:51 pm
saadishah wrote:Adam and Brianna plan to install a new tile floor in a classroom. Adam works at a constant rate of 50 tiles per hour, and Brianna works at a constant rate of 55 tiles per hour. If the new floor consists of exactly 1400 tiles, how long will it take Adam and Brianna working together to complete the classroom floor?

A. 26 hrs. 44 mins.
B. 26 hrs. 40 mins.
C. 13 hrs. 20 mins.
D. 13 hrs. 18 mins.
E. 12 hrs. 45 mins.

The solution to this problem came so easy that I feel like I am making some mistake :-)

Here is how I have solved it:

Combined Rate of A + B = 50 + 55 = 105
Total tiles = 1400
Time needed to finish 1400 tiles = 1400/105 = 13 hours and 35/105 minutes which simplifies to be 13 hours 20 minutes.

So option C.
Your solution is perfect.
Answer: C

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
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by [email protected] » Wed Sep 28, 2016 9:59 am
Hi saadishah,

As you continue to study, you're going to find that many of the GMAT Quant questions that you face are actually fairly straight-forward. The "work" that you have to complete often takes just a minute (or less) and the rest of your time is spent reading, taking notes and deciding which approach will get you to the correct answer in the most efficient way. While 'word problems' will certainly take longer to read than other (less-wordy) Quant questions, that doesn't mean that they're necessarily going to be that difficult. So you should stay calm (regardless of how wordy the prompt is), take notes and do all of the work on the pad.

GMAT assassins aren't born, they're made,
Rich
Contact Rich at [email protected]
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by Matt@VeritasPrep » Thu Sep 29, 2016 6:35 pm
Rule of thumb:

If you're working from a book, and a solution seems too easy to be right, there's a very good chance IT IS that easy and you're right.

If you're working from a CAT, and a solution seems too easy to be right, there's a very good chance IT IS NOT that easy and you're wrong.

This rule has saved me a lot of headache over the years ... but I still screw up anyway sometimes. :D
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