Question

A can laid railway track between two given stations in 16 days and B can do the same job in 12 days. With help of C, they did the job in 4 days only. How many days will C complete the work alone?

• A.
• B.
• C.
• D.

Answer 1

The correct option is A

1 day’s work of (A + B + C) = $\frac{1}{4}$

A’s 1 day’s work = $\frac{1}{16}$

B’s 1 day’s work = $\frac{1}{12}$

So, C’s 1 day’s work $=\frac{1}{4}-(\frac{1}{6}+\frac{1}{12})$

$=(\frac{1}{4}-\frac{7}{78})=\frac{5}{48}$

C alone can do the work in $\frac{48}{5}$ days.