arslanama wrote:

A cylindrical bucket, with height 10 and radius r , is 3/4 filled with water. A boy is dropping marbles with volume r/10 into the bucket at a rate of 12 per minute.

How many seconds will it take before water overflows from the bucket?

(A) 2.1rπ

(B) 25rπ

(C) 125rπ

(D) 300rπ

(E) 375rπ

Hi

Volume of cylinder=π*r^2*10=10πr^2

Now 1/4 is vacant, so marbles have to fill up 10πr^2/4=5πr^2/2..

Since ans is per second, marbles per sec 1/5, so volume per second=1/5*r/10=r/50...

Number of seconds= \(\frac{5πr^2}{2}*\frac{50}{r}\)=125πr..

C

_________________

1) Absolute modulus : http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372

2)Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html

3) effects of arithmetic operations : https://gmatclub.com/forum/effects-of-arithmetic-operations-on-fractions-269413.html

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