Subject: General Aptitude · Chapter: Time and Work · Exam: · Marks: · Difficulty:
A does $\frac{4}{5}$ of a work in 20 days. He then calls in B and they together finish the remaining work in 3 days. How long B alone would take to do the whole work ?
(a)23 days
(b)37 days
(c)$37 \frac{1}{2}$ days
(d)40 days
Answer
Answer (as printed): C
Explanation
Whole work is done by A in 20 × = 25 days. 4 4 1 Now, 1 − i.e., work is done by A and B in 3 days 5 5 Whole work will be done by A and B in (3 × 5) = 15 days. 1 1 A’s 1 day’s work = , (A + B)’s 1 day’s work = . 25 15 1 1 4 2 ∴ B’s 1 day’s work = − = = . 15 25 150 75 75 1 So, B alone would do the work in = 37 days. 2 2 QUANTITATIVE APTITUDE
Explanation as extracted from the printed page; notation may be imperfect.