What is a% of b?

Question

What is a% of b?

(1) 200% of a% of b = 360
(2) b% of a = 180

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minustark · Answer

a% of b = a/100*b or, ab /100. So, basically the question is asking whether we can derive the value of ab/100 from the given information.

Statement 1 :

200% of a% of b = 360 
or, 2a% of b =360
or, 2a/100* b = 360
or, 2ab/100 =360
So, ab/100 = 180. SUFFICIENT

Statement 2 :

b% of a = 180
or, b/100* a = 180
So, ab/100 = 180. SUFFICIENT

Answer: D

nzil · Answer

1) 200% of a% of b=360

i.e 2a% X b =360
2ab/100=360
ab/100=180
suff

2) b% of a = 180

as we know a% of b = b% of A
sufficient

IMO D

Posted from my mobile device

saukrit · Answer

a% of b =  \frac{ab}{100}

Statement 1) 200% of a% of b =360 
 \frac{200}{100}  *  \frac{ab}{100}  =360
 \frac{ab}{100} = 180 SUFFICIENT.   Cross off B,C and E

Statement 2 b% of a =180
 \frac{ab}{100} =180 SUFFICIENT.   Cross off A. 
 
 Hence D is correct

EMPOWERgmatRichC · Answer

OFFICIAL EXPLANATION
 
Hi All,

We're asked what is A% of B. This question can be solved with Arithmetic or by TESTing VALUES.

(1) 200% of A% of B = 360

IF....
A = 100, then 200% of 100% of B = 360.... Since 100% of B would be "all" of B, taking 200% of that number would mean DOUBLING the value of B and getting 360. This means that B would equal 180. The answer to the question is... 100% of 180 = 180

A = 10, then 200% of 10% of B = 360. From our prior example, we know that taking 200% of a number means DOUBLING the number. Here, we would have 20% of B equaling 360... 
(.2)(B) = 360 
B = 1800.... The answer to the question is... 10% of 1800 = 180

No matter what values you TEST, the answer to the question will ALWAYS equal 180.
Fact 1 is SUFFICIENT

(2) B% of A = 180

IF....
B = 100, A = 180... The answer to the question is 180% of 100 = (1.8)(100) = 180
B = 50, A = 360... The answer to the question is 360% of 50 = (3.6)(50) = 180

No matter what values you TEST, the answer to the question will ALWAYS equal 180.
Fact 2 is SUFFICIENT

Final Answer:  D

GMAT assassins aren't born, they're made, 
Rich

MHIKER · Answer

(1) 200% of a% of b = 360; a% of b =360/200%; Sufficient

(2) b% of a = 180; b/100*a=180; ab/100=180; b*a/100=180; b*a%=180; Sufficient.

The answer is D

What is a% of b?

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