Subject: General Aptitude · Chapter: Time and Work · Exam: · Marks: · Difficulty:
A, B and C can do a piece of work in 36, 54 and 72 days respectively. They started the work but A left 8 days before the completion of the work while B left 12 days before the completion. The number of days for which C worked is
(a)4
(b)8
(c)12
(d)24
Answer
Answer (as printed): D
Explanation
Suppose the work was finished in x days. Then, A’s (x – 8) days’ work + B’s (x – 12) days’ work + C’s x days’ work = 1 ( x − 8) ( x − 12) x ⇒ + + =1 36 54 72 ⇔ 6 (x – 8) + 4 (x – 12) + 3x = 216. ∴ 13x = 312 or x = 24. t 97. (20 × 16) women can complete the work in 1 day. 1 ∴ 1 woman’s 1 day’s work = . 320 (16 × 15) men can complete the work in 1 day. 1 ∴ 1 man’s 1 day’s work = . 240 1 1 : = 4 : 3. So, required ratio = 240 320 1
Explanation as extracted from the printed page; notation may be imperfect.