Subject: General Aptitude · Chapter: Time and Work · Exam: · Marks: · Difficulty:
A and B together can do a piece of work in 12 days, which B and C together can do in 16 days. After A has been working at it for 5 days and B for 7 days, C finishes it in 13 days. In how many days $C$ alone will do the work ?
(a)16
(b)24
(c)36
(d)48
Answer
Answer (as printed): B
Explanation
A's 5 days' work + B's 7 days' work + C's 13 days' work $=1 \Rightarrow$ (A+B)'s 5 days' work + (B+C)'s 2 days' work + C's 11 days' work $=1 \Rightarrow \frac{5}{12}+\frac{2}{16}+$ C's 11 days' work $=1 \Rightarrow$ C's 11 days' work $=1-\left(\frac{5}{12}+\frac{2}{16}\right)=\frac{11}{24} \Rightarrow$ C's 1 day's work $=\frac{11}{24} \times \frac{1}{11}=\frac{1}{24}$. $\therefore$ C alone can finish the work in 24 days.
Explanation as extracted from the printed page; notation may be imperfect.