Monday, December 21, 2009

GMAT question of the day

A can is full of paint. Out of this 5 litres are removed and thinning liquid
substituted. The process is repeated. Now the ratio of paint to thinner is 49 :
15. What is the full capacity of the can?

(a) 20 litres
(b) 60 litres
(c) 40 litres
(d) 50 litres

If the can contains x litres of paint,

The ratio of paint to thinner is

(x - 5)/x

Since the process is repeated we can square the values

[(x - 5)/x]^2 = 49: (49 +15) .

(x - 5)/x =7: 8

X= 40 litres.