A can do a piece of work in 10 days, while A and B together can complete it in 21/2 days. How long will B alone take to complete the work?

A can do a piece of work in 10 days, while A and B…

A can do a piece of work in 10 days, while A and B together can complete it in $2\frac{1}{2}$ days. How long will B alone take to complete the work?

Show answer & explanation

Correct answer: B

Explanation

The correct answer is Option 2 i.e. $\rm \frac{10}{3} \ days$ .

Work done by A each day = 1/10

Let, the time taken by B be x

According to the question

⇒ 1/10 + 1/x = 2/5

⇒ 1/x = 2/5 - 1/10

⇒ 1/x = (4 - 1)/10

⇒ 1/x = 3/10

⇒ x = 10/3

Therefore, B alone alone will take $\rm \frac{10}{3} \ days$ to complete the work