Subject: General Aptitude · Chapter: Time and Work · Exam: 2006 · Marks: · Difficulty:
A man, a woman and a boy can do a piece of work in 6, 9 and 18 days respectively. How many boys must assist one man and one woman to do the work in 1 day?
(a)5
(b)6
(c)9
(d)13
Answer
Answer (as printed): D
Explanation
(1 man + 1 woman)'s 1 day's work $=\left(\frac{1}{6}+\frac{1}{9}\right)=\frac{5}{18}$. Remaining work $=\left(1-\frac{5}{18}\right)=\frac{13}{18}$. Work done by 1 boy in 1 day $=\frac{1}{18}$. $\therefore$ Number of boys required $=\left(\frac{13}{18} \times 18\right)=13$.
Explanation as extracted from the printed page; notation may be imperfect.