the UV rating

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the UV rating

by sanju09 » Thu May 13, 2010 6:07 am
The time it takes to get sunburn varies inversely as the UV rating. At a UV rating of 6 the time it takes to get sunburn can be as little as 15 minutes. What's the time, in minutes, it will take to get sunburn when the UV rating is 10?
(A) 20
(B) 18
(C) 12
(D) 9
(E) 6
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by Gmat_War » Thu May 13, 2010 6:13 am
IMO D.This is a sum of variation.
If UV rating is termed as x and time is t,then as per the logic:
x varies inversely to t
So, x=k/t where k is a constant.
Using x=6 and t=15 ,k=90.
Putting value of k and value of x=10,we can get time t=9 minutes.
OA please

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by gmatmachoman » Thu May 13, 2010 6:41 am
Inverse Proportion:

6*15/10

=9