Question

A and b can do a work in 30 days. B and c in 20 days. A starts the work and works on it for 5 days.Then b takes it up and work for 15 days and finally c finishes the work ind 18 days. In how many days can c alone do the work?

Answer 1

Step-by-step explanation:

According to the question, 

=A+B........30A+B........30days 

=B+C.............20B+C.............20

=A........ 5 

=B.........5+10

=C..........10+8

= Work done by(A+B) in 5 days 

= 2×5=10

Work done by(B+C) in 5 days 

= 10×3=30 work 

Total work (finished till now)..........40 units 

=Remaining work =60−40

= 20 units 

= Here we find that C does remaining 20 units 

in 8 days 

C's efficiency = Work/Day=20 Work/8 Days=5/2

C's efficiency =5/2 unit/day

Therefore, time taken by C alone to complete the work =60/5×2=24 days