Saturday, January 2, 2010

GMAT Question Of the Day

A can complete a job in 9 days, B in 10 days and C in 15 days. B and C start
the work and are forced to leave after 2 days. The time taken to complete the
remaining work is:

(a) 6 days
(b) 9 days
(c) 10 days
(d) 13 days

Assume 90 units of work have to be done.

No. of unit done by A in one day = 90/9 =10 units

B in one day = 90/10 = 9 units

C in one day = 90/15 = 6 units

Work done by B and C in 2 days = (9 + 6) x 2
= 30 units
Remaining work = 90 – 30 = 60 units

∴ Time taken by A = 60/10
= 6 days