Water is leaking out from a cylinder container...

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Water is leaking out from cylinder container at the rate of 0.31 m^3 per minute. 10 minutes later, the water level decreases 0.25 meter. What is value of the radius?

(A) 0.5
(B) 1.0
(C) 1.5
(D) 2.0
(E) 2.5

The OA is D.

I'm confused with this PS question. Experts, any suggestion? How can I colve this question? Thanks in advance.

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by EconomistGMATTutor » Thu Jan 11, 2018 8:42 am
Hello LUANDATO.

Let's take a look at your question.

The volume of a cylinder container is $$V=\pi\cdot r^2\cdot h .$$ Now, we know that after 10 minutes it has been leaked out $$0.31\cdot10=3.1\ m^3\ of\ water.$$ On the other hand the water has decreased 0.25 meter. We now can build a cylinder of volumen 3.1m^3 and height 0.25. Then $$3.1=\pi\cdot r^2\cdot0.25\ \Leftrightarrow\ \ r^2=3.947\ \Leftrightarrow\ r=1.98.$$ This is why the correct answer is the option D.

I hope this answer can help you.

I'm availbale if you'd like a follow-up.

Regards.
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