Question

A can do a piece of work in 10 days and b can do it in 15 days and c can do it 20 days. they started the work together and a leaves after 2 days and b leaves after 4 days from the beginning. how long will work lost?

Answer 1

hi friends in this problem we solve

simple methods

by lcm method

A = 10 , B = 15 , C = 20

LCM is total work

lcm = 60 unit

one days work in unit of each

60/10 = 6 unit

60/15 = 4 unit

60/20 = 3 unit

A + B + C = 6 + 4 + 3 = 13 unit per days

work together 2 days

13 × 2 = 26 unit done

after 2 days a

Now B + C = 4 + 3 = 7 unit

together do 4 days

7 × 4 = 28 unit

work done = 26 + 28 = 54 unit

work remaining = 60 - 54 = 6 unit

C do in = 6/3 = 2 days

total work done in

2 + 4 + 2 = 8 days