Subject: General Aptitude · Chapter: Time and Work · Exam: · Marks: · Difficulty:
A and B can do a piece of work in 30 days, while B and C can do the same work in 24 days and C and A in 20 days. They all work together for 10 days when B and C leave. How many days more will A take to finish the work ?
(a)18 days
(b)24 days
(c)30 days
(d)36 days
Answer
Answer (as printed): A
Explanation
2 (A + B + C)’s 1 day’s work = + + = = . 30 24 20 120 8 1 ⇒ (A + B + C)’s 1 day’s work = . 16 10 5 Work done by A, B and C in 10 days = = . 16 8 5 3 Remaining work = 1 − = . 8 8 1 1 1 A’s 1 day’s work = − = . 16 24 48 s. 1 Now, work is done by A in 1 day. 48 3 3 So, work will be done by A in 48 × = 18 days. 8 8 1 1
Explanation as extracted from the printed page; notation may be imperfect.