Question

A and B together can finish a piece of work in 12 days. If ‘A’ alone can finish the same work in 20days , in how many days B alone can finish it?

Answer 1

A and B take 12 days to complete the work.
⇒A and B's 1 day's work=$\frac{1}{12}$
A takes 20 days to complete the work.
⇒A's 1 day's work=$\frac{1}{20}$
⇒B's 1 day's work=$\frac{1}{12}- \frac{1}{20}$
=$\frac{1*5-1*3}{60}$
=$\frac{2}{60}= \frac{1}{30}$
⇒B can do the work in $\frac{1}{ \frac{1}{3 0}}$=30 days.
Ans:B alone will finish the work in 30 days.
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