Subject: General Aptitude · Chapter: Time and Work · Exam: 2005 · Marks: · Difficulty:
$A$ does half as much work as $B$ in one-sixth of the time. If together they take 10 days to complete a work, how much time shall $B$ alone take to do it?
(a)30 days
(b)40 days
(c)50 days
(d)70 days
Answer
Answer (as printed): B
Explanation
Suppose B takes $x$ days to do the work. $\therefore$ A takes $\left(2 \times \frac{x}{6}\right) = \frac{x}{3}$ days to do it. (A+B)'s 1 day's work $= \frac{1}{10}$. $\therefore \frac{3}{x}+\frac{1}{x}=\frac{1}{10} \Rightarrow \frac{4}{x}=\frac{1}{10} \Rightarrow x=40$.
Explanation as extracted from the printed page; notation may be imperfect.