Subject: General Aptitude · Chapter: Time and Work · Exam: 2007 · Marks: · Difficulty:
A, B and C can complete a work in 10, 12 and 15 days respectively. They started the work together. But A left the work 5 days before its completion. B also left the work 2 days after A left. In how many days was the work completed?
(a)4
(b)5
(c)7
(d)8
Answer
Answer (as printed): C
Explanation
C’s 3 days’ work = × 3 = . 15 5 1 1 3 3 (B + C)’s 2 days’ work = + × 2 = × 2 = . 10 12 15 20 1 3 1 1 Remaining work = 1 – + = 1 – = . 5 10 2 2 1 1 1 15 1 (A + B + C)’s 1 day’s work = + + = = . 10 12 15 60 4 1 work is done by A, B and C in 1 day. 4 1 1 \ work is done by A, B and C in 4 × = 2 days. 2 2 Total number of days = (3 + 2 + 2) = 7.
Explanation as extracted from the printed page; notation may be imperfect.