GMAT prep test question 1

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GMAT prep test question 1

by mate2012 » Fri Mar 23, 2012 7:47 am
Hello everyone,

as there are no explanations on the preptest I need your help to resolve this problem.

Could someone please explain to me how to get to the right answer "m=35"

Thanks in advance!

(1/5)^m * (1/4)^18 = [1/2*(10)^35]

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by killer1387 » Fri Mar 23, 2012 8:47 am
(1/5)^m * (1/4)^18 = [1/2*(10)^35]
=>(1/5)^m=2^36/(2*2^35*5^35)=2^36/(2^36*5^35)=(1/5)^35
=> m=35

hope this helps...!!

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by ShrutiN » Fri Mar 30, 2012 3:29 am
Simply break down the 10=2*5 on the right hand side;

You'll get the power of 1/5 as 35 on the Right side
Oh the left side the power of 1/5 is m
As both should be equal m=35

The use of reciprocals can make the question confusing, if you are not comfortable with reciprocals, you can write: (1/5)^m as 5^-m Then you'll be able to solve all such problems very easily.

Hope that helps!!