Subject: General Aptitude · Chapter: Time and Work · Exam: · Marks: · Difficulty:
A, B and C can do a piece of work in 11 days, 20 days and 55 days respectively, working alone. How soon can the work be done if A is assisted by B and C on alternate days?
(a)7 days
(b)8 days
(c)9 days
(d)10 days
Answer
Answer (as printed): B
Explanation
(A + B)’s 1 day’s work = + = . 11 20 220 1 1 6 (A + C)’s 1 day’s work = + = . 11 55 55 31 6 55 1 Work done in 2 days = + = = . 220 55 220 4 1 Now,work is done in 2 days. 4 ∴ Whole work will be done in (2 × 4) = 8 days. TIME AND WORK 1 1
Explanation as extracted from the printed page; notation may be imperfect.