Two GMAT Prep Questions that I dont agree with

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Junior | Next Rank: 30 Posts
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Hello,

The two questions below I cannot agree with GMAT's answers. Can anyone explain how their answers are correct?

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Here I believe the answer is 25, GMAT says it is 20. My logic is as follows:
The cyclist at 20mph got 1.666 miles in 5 mins (5mins is 1/12th of an hour --> 20/12 = 1.666). The hiker went a mile every 15 minutes (a third of a mile every 5 mins). Therefore, it took the hiker 15 mins to do the first mile, and 10 mins to do the next 2/3's of the distance. 15+10 =25, not 20. Is my logic flawed?

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I believe both statements are insufficent, GMAT says it is solveable with both. My logic is as follows: Statement 2 says X > Y. Therefore, we can plug #'s into statement one.

First I used X =3, Y=2.5 --> 2(3)-2(2.5) ---> 6-5 =1, X and Y positive work.

Now lets try some negative numbers. X=-2, Y=-2.5 ---> 2(-2) - 2(-2.5) ---> -4 +5 = 1

We can solve it with both x and y positive, and x and y negative, therefore we dont know if x and y are both positive.... I said E, they say C.

Thanks,
-Dave[/img]
Source: — Problem Solving |

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by vishubn » Wed Nov 05, 2008 7:49 pm
Question with hiker

The hiker travels for (20*5)/60 miles =5/3 miles in 5 min before he waits for the hiker.

The hiker travles (4*5)/60 miles =1/3 miles in the meantime.

So, the cyclist needs to wait until the hiker cover (5/3)-(1/3) miles ie 4/3 miles

To cover this distance the hiker needs, (4/3)* (60/4) =20min

Vishu

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by vishubn » Wed Nov 05, 2008 8:00 pm
https://www.beatthegmat.com/equatons-are ... 16917.html

The above post is the for the second question !!

i realized both the question is bening answered

p.s. please search and also try and post one question at a time :)

Vishu