Question

Kshitij can do a piece of work in 20 days and Rohan can do the same work in 15 days. they worked together for 5 days and then Rohan leaves. in how many days will Kshitij alone finish the remaining work?

Answer 1

Kshitij's 1 day's work= 1/20th part
Rohan's 1 day's work= 1/15th part
Both's 1 day's work= 1/20+1/15= 3+4/60 = 7/60 the part
Both's 5 day's work= 7/60*5 = 7/12th part
Remaining work= 1-7/12 = 5/12th part
Time required by Kshitij = 5/12/1/20= 25/3 days = 8 1/3 days

Answer 2

Kshitij will take 3.125 days to complete the work.

• Kshitij can do a piece of work in 20 days and Rohan can do the same work in 15 days.

• Kshitij's 1 day work will be 1/20.

• Rohan's 1 day work will be 1/15.

• Now they worked together for 5 days and the rohan leaves.

• Now the total work done by both of them in 5 days = 5(1/20 + 1/15) = 7/12 part of the work.

• Now Rohan leaves and now Kshitij has to finish the work alone.

• Remaining part of the work  = 1 -7/12 = 5/12

• Now the number of days required for Kshiitij to complete the work alone = $\frac{5/12}{1/20}$ = 3.125 = 8$\frac{1}{3}$ days