Question

4. A and B can do a piece of work in 30
days, B and C can do it in 40 days and C
and A can do it in 60 days. In how many
days A, B and C can finish the work
together?​

Answer 1

Answer:

Step-by-step explanation:

A + B = 30 days

B + C = 40 days

C + A = 60 days

Let's take totak work as LCM of 30,40 and 60 = 120 units

Their unit work in a day will be

A + B = 120/30 = 4 units/day

B + C = 120/40 = 3 units/day

C + A = 120/60 = 2 units/day

Add these equations

2A + 2B + 2C = 4+3+2

2(A + B + C) = 9

A + B + C = 9/2 units per day

Therefore to complete 120 units they'll take a time of

= 120/(9/2)

= 120*2/9 = 40*2/3

= 80/3 days (Ans)

Or 26,2/3 days (mixed fraction format)