Question

a nad b can do a piece of work in 15 days ; c and a in 20 days. In how many days will a,b and c will together complete the work
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Answer 1

Answer:

Thus all three can do the work in 10 days

Step-by-step explanation:

Please make correction as:

A and B can do a piece of work in 12 days. B and C in 15 days and C and A in 20 days.If A,B and C work together, they will complete the work in :

Their On day's work are as:

a+b=1/12

b+c=1/15

c+a=1/20

adding three we get

2(a+b+c) =1/12+1/15+1/20

=1/60(5+4+3)=12/60

a+b+c=1/10

Thus work of three in one day=1/10

Thus all three can do the woprk in 10 days