Question

A and B Can complete a price of work in 5 and 10 days. they work together and after two days C joins them. If C alone takes 10 days to do work, how long will all three take to complete the work?​

Answer 1

Answer:

A+B work for 12 days and complete 1/3 rd of the work. Hence to do the whole work they will require 36 days.

A alone takes 60 days, hence B alone takes 1/36 - 1/60 =2/180 or 90 days.

2/3rd of the work is completed by A+C in 20 days hence the whole work can be completed by them in 30 days

A alone takes 60 days ( given) hence C alone takes 1/30 - 1/60 = 60 days

Now A alone takes 60 days

B alone takes 90 days and

C alone takes 60 days.

Taking LCM 180 as total work, A's efficiency =3, B's efficiency=2 and C's efficiency =3. A+B+C efficiency =8 units per day.

Time required to do the job together = 180 ÷ 8 =:22.5 days.