GMAT PREP I TREE

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GMAT PREP I TREE

by pkw209 » Wed Dec 30, 2009 3:56 pm
Hi,

I solved this question through backsolving but was hoping someone could explain this one algebraically. FYI, I got this from Zuleron's list of 198 gmat prep questions. The answer is D. Thanks!

97) When a tree was planted it was 4 feet. Its height increased by a constant amount each year for 6 years. After 6 years the tree was 1�5 taller than at the end of 4th year. By how many feet did the height of the tree increase each year?

a. 3�10
b. 2�5
c. 1�2
d. 2�3
e. 6�5
Source: — Problem Solving |

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by ace_gre » Wed Dec 30, 2009 4:55 pm
Let the amount gained by the tree each year be x.

So end of 1st year tree is 4+x
end of 2nd year tree is 4+2x...end of 6th year tree is 4+6x.

Also given 4+6x = 1 1/5*(4+4x).
Solving for x = 2/3.

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by hmboy17 » Wed Dec 30, 2009 9:34 pm
pwk209,
Could you please send me the "Zuleron's list of 198 gmat prep questions" ?
My email id - [email protected]