Question

A and B can do a piece of work in 72dayss B, And C can do it in 120 days and A and C can do it in 90 days when A, B and C work together, how much work is finished by them in 3 days

Answer 1

Answer:

(A and B)'s 1 days work = 1/72.

(B and C)'s 1 days work = 1/120. (C and A)'s 1 days work = 1/90.

By adding we get,

2(A+B+C)'s 1 days work=2(1/72+1/120+1/90)

LCM of 72,120,90= 360

5+3+4 by 360

= 12 by 360

therefore ;(12/360)

=1 by 30 or 1/30

= 1/30 multiply by 1/2= 1/60

(A+B+C)'s 1 days work if they do it together=60

tHerefore;

(A+B+C)'s 3 days work is 60 mulitiply by 3= 120 days.

So, your answer is 120 days.