Question

5
A, B and C working together can do a piece of work in 8 hours. A alone can do it in 20 hours
and B alone can do it in 24 hours. In how many hours will C alone do the same work?​

Answer 1

Answer:

30 hours

Step-by-step explanation:

A can complete the work in 20 hr alone

B can complete the work in 24 hr alone

work done by A in 1 hr =1/20

work done by B in 1hr=1/24

time taken by A+B+C together to do the work =8hrs

work done together by A,B,C in 1hr= 1/8

work done by C per hr=work done by A,B,C together in 1hr - work done per hr by A -work done per hour by B

=1/8-1/24-1/20 =1/30

thus

the time taken by C alone to do the work is 30 hrs

this is the correct answer