If a = 4b, what percent of 2a is 2b?

Question

(A) 10% 
(B) 20% 
(C) 25% 
(D) 26% 
(E) 40%

Source:   Nova GMAT  
Difficulty Level:   550

GMATinsight · Answer

Let, x% of 2a = 2b

I.e. (x/100)*(2a)= 2b
I.e. x= 100b/a = 100/4= 25

Answer option C

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amanvermagmat · Answer

What % of 2a is 2b? Or 2b is what % of 2a? This = 2b/2a * 100 = b/a * 100
So basically we need b/a

We are given a=4b, so b/a = 1/4. Therefore our answer = 1/4 * 100 = 25%

Hence  answer is C

Abhishek009 · Answer

Let b = 1

So, a = 4

So, we have 2a = 8 & 2b = 2

\frac{2}{8}*100  =  25 %

Thus, answer will be (C) 25 %

JeffTargetTestPrep · Answer

Simplifying, we have:

b/a = 1/4

2b/2a = 1/4 as well, which is 25%.

Answer: C

AlanGonzales · Answer

X percent of 2a is 2b 
It means that 2b = 100 percent 
x/100 * 2a= 2b 
x/100 = 2b/2a
x/100 = b/a
x = 100b/a = 100/4 = 25
Answer is C

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