Question

A and B together can complete a piece of work in 4 days. If A alone can complete the same work in 12 days, in how many days can B alone complete that work?

• A. 8 days
• B. 6 days
• C. 5 days
• D. 4 days
• E. None of these

Answer 1

The correct option is B

6 days

(A+B)’s 1 day’s work = $\frac{1}{4}$

A’s 1 day’s work = $\frac{1}{12}$

B’s 1 day’s work = $\frac{1}{4}-\frac{1}{12}=\frac{1}{6}$

Hence, B alone can complete the work in 6 days.