Question

A and b start working together after some days a left the work and the whole work completed in 9 days .Find after how many days did a left

Answer 1

A worked for 4 days...

Answer 2

Complete question:

A and B start working together after some days, A left the work and the whole work completed in 9 days. Find after how many days did A left, if A and B completed the work in 10 and 15 days, respectively?

Answer:

A left on 3rd day, if A and B completed the work in 10 and 15 days.

Step-by-step explanation:

Number of days A took to complete the work = 10 days

Work done by A in 1 day = 1/10

Number of days B took to complete the work = 15 days

Work done by B in 1 day = 1/15

Work done by A and B in 1 day = 1/10 + 1/15 = 5/30 = 1/6

Number of day B worked after A = 9 days

Work done by B in 9 day = 1/15 × 9 = 3/5

Work done by A and B in the beginning = 1 - 3/5 = 2/5

Now, the days to complete 2/5 part of work = 2/5 ÷ 1/6 = 12/5 = 2.4 ≈ 3 days