The number of cars present at a particular time was measured at 3,999

Question

The number of cars present at a particular time was measured at 3,999 different locations on Tuesday and on Wednesday. The number of locations that had more cars on Wednesday was 15% higher than the number of locations that had more cars on Tuesday. How many of the locations had more cars on Tuesday?

Let the no. of cars on Tuesday = x
therefore, the no. of cars on Wednesday = 1.15x

=> x+1.15x = 3999
=> 2.15x=3999
=> x = 3999/2.15 = 1860

Hence C

A. 1,159
B. 1,333
C. 1,860
D. 2,460
E. 2,829

lacktutor · Answer

Tues+Wed=3999

--> Wed=1.15*Tues
Tues+1.15*Tues=3999
2.15*Tues=3999
Tues= \frac{3999}{2.15} = \frac{3999}{(215/100)} = \frac{3999}{(43/20)} =93*20=1860

The answer is C.

eakabuah · Answer

From the question stem, w+t=3999 .......(1)
we also know that w=(1+15/100)t =1.15t .....(2)
Substitute w=1.15t into (1) yields
1.15t + t = 3999
2.25t=3999
t=3999*100/215 = 79980/43 = 1860.

The answer is therefore C

Posted from my mobile device

garcmillan · Answer

This question is a good example of how important it is to get used to approximation in non-trivial calculations. Saving some seconds in questions of this kind is critical to have extra ones in +700 questions.

In this question, it is also important to realize from the beginning that we are not looking for number of cars, but locations where there were more number of cars. This is important to not lose some valuable seconds

As lacktutor explained, we need to translate the problem into these two equations:

T+W=3999
W=1.15*T

From this we get the equation 2.15*T=3999

Now we need to solve T=3999/2.15

After coming up with this equation we shouldn't spend more than 5 seconds to choose option C. How?

This is what you should do in your mind to choose the option C in less that 5 seconds:

1) Check beforehand that options are sufficiently spread out to approximate
2) T=4000/2 = 2000
3) T= 4000/3 = 1333 (I bet you can do this calculation in less than 2 sec)
4) Check answers: which option is between 2000 and 1333?

Option C!

You need to get used to building up this kind of habits so that you can save valuable seconds, seconds that will play a crucial role in +700 questions.

Paras96 · Answer

The number of cars present at a particular time was measured at 3,999 different locations on Tuesday and on Wednesday. The number of locations that had more cars on Wednesday was 15% higher than the number of locations that had more cars on Tuesday. How many of the locations had more cars on Tuesday?

Let the no. of cars on Tuesday = x
therefore, the no. of cars on Wednesday = 1.15x

=> x+1.15x = 3999
=> 2.15x=3999
=> x = 3999/2.15 = 1860

Hence C

Let the no. of cars on Tuesday = x
therefore, the no. of cars on Wednesday = 1.15x

=> x+1.15x = 3999
=> 2.15x=3999
=> x = 3999/2.15 = 1860

Hence C

The number of cars present at a particular time was measured at 3,999

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GMAT Problem Solving (PS) Questions

The number of cars present at a particular time was measured at 3,999

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards