2 problems from gmatprep

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2 problems from gmatprep

by xcise_science » Fri Dec 07, 2007 8:59 am
Q37
answer is C
Image


Q15
Image

thanks

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by me4mba » Fri Dec 07, 2007 10:39 am
Q37: First, we have to figure out how far the hiker is from the biker after 5 minutes. Since they're both traveling in the same direction, you can subtract the smaller rate from the bigger rate to get the overall rate.

So, the biker and the hiker were getting further away from each other at the rate of 20-4 = 16 mile per hour, or 16 mile per 60 minutes. After 5 minutes, they will be:

(16 miles / 60 minutes) x 5 minutes = 4/3 miles apart.

The question asks how long the biker have to wait for the hiker to catch up with him.

(4/3 miles) x (60 minutes / 4 miles) = 20 minutes.

For the other question- I think that when you have a triangle whose two legs are of constant length, the triangle's area is maximized when the 2 legs come together at 90 degree.

In this case, we know that the length of each legs are 1 because that's the radius of the circle (given).

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by xcise_science » Wed Dec 12, 2007 8:58 am
Hi,
I don't understand how you concluded that its a right triangle thats formed.

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by jayhawk2001 » Wed Dec 12, 2007 10:01 am
xcise_science wrote:Hi,
I don't understand how you concluded that its a right triangle thats formed.
Please check

https://www.beatthegmat.com/ps-t6611.html