Question

Gautam and Mahesh can do a piece of work in 10 days and 20 days, respectively. With Jayant's help, they can complete the whole piece of work in 5 days. How many days will Jayant alone take to complete the work?​

Answer 1

Given:

Mahesh can do the work in 10 days and Umesh can do the same work in 15 days. Mahesh started the work alone and after 5 days Umesh joined with him and they complete the work together.

Concept Used:

Concept of work and time

Calculation:

Mahesh can do the whole work in 10 days

In 1 day, Mahesh can do 1/10 part of the work

In 5 days, he can complete 5/10 = ½ of the work

Remaining work = (1 – ½) = ½ part

Umesh can do the work in 15 days

In 1 day, Umesh can do 1/15 part of the work

In 1 day together they can do (1/10 + 1/15) part of the work

⇒ (3 + 2)/30

⇒ 1/6 part of the work

Together they can do 1/6 part work in 1 day

Together they can do ½ part work in (½ × 6) = 3 days

∴ Together in 3 days, the remaining work will be complete.