Question

a and b can do a piece of work in 72 days, 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

a+b =72

a+c=90

b+c=120

2(a+b+c+)=282

a+b+c=141 days for work done

for 3 days,

3/141=1/47 work complete

Answer 2

Answer:

Step-by-step explanation:

(A+B)'s 1 day work = 1/72

(B+C)'s 1 day work = 1/120

(A+C)'s 1 day work = 1/90

Together the work will be done= 1/72+1/120+1/90

5+3+4/360

=12/360

=1/30

Three people can complete the work = 1/30×3

=3/30

=1/10

=10 days

They can finished work in 3 days = 10 days