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fashion continues without break

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by sanju09 » Wed Jun 11, 2014 1:33 am
A monkey is trying to reach on top of a 30 meter high greasy electric pole in such a way, that it ascends by 2 meters in the first minute, it descends by 1 meter in the second minute, ascends by 2 meters in the third minute, descends by 1 meter in the fourth minute, and so on. If this fashion continues without break, after how many minutes of its start from the base of the electric pole, will the monkey be able to reach on the top of it?
(A) 60
(B) 57
(C) 56
(D) 48
(E) 30



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The mind is everything. What you think you become. -Lord Buddha



Sanjeev K Saxena
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The Princeton Review - Manya Abroad
Lucknow-226001

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Source: — Problem Solving |

by theCodeToGMAT » Wed Jun 11, 2014 4:53 am
+2 -1 +2 -1 .......... ==> So, in 2 minutes = 1 meter

1 meter = 2 minutes
28 meter = 56 minutes..
Now, it ascends 2 meter... So, 30 meter = 57 seconds

[spoiler]{B}?[/spoiler]
R A H U L
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by Mathsbuddy » Fri Jun 13, 2014 8:34 am
Metres Seconds
2 1
3 3
4 5
5 7
N 2N - 3

N = 30 60 - 3 = 57
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by sanju09 » Sun Jun 22, 2014 12:19 am
Good approaches friends :)

Another one...

In order to reach on the top of the pole, the last leap of the monkey must be an ascend (2-meter rise takes 1 minute), hence, let's focus on the time taken in reaching to the remaining 28 meters up the base.

Since it starts from an ascend of 2 meters in the first minute, and a descend of 1 meter in the next minute, hence, ideally, its rate is always 1 meter rise per 2 minutes. Hence, a 28 meters rise would take the monkey 56 minutes, add 1 minute of the last leap and answer [spoiler](B) 57.[/spoiler]
The mind is everything. What you think you become. -Lord Buddha



Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001

www.manyagroup.com
Join the discussion