Question

Aand b together can do a piece of work in 24 days ; b and c together can do it in 20 days and c and a together can do it in 30 days . They all work together for 12 days , where a and b leave . How many days more will take to finish the work ?

Answer 1

Answer:

Step-by-step explanation:

Let a,b and c work done by in one day and 120w is full work then

24(a+b)=120w

a+b=5w----(1)

20(b+c)=120w

b+c=6w----(2)

30(c+a)=120w

c+a=4w----(3)

addind(1),(2) and (3) we get

2(a+b+c)=15w

a+b+c=15w/2

work done by a,b and c in 12 days=12(a+b+c+)=6*15w=90w

remaining work =120w-90w=30w

now (2)+(3)-(1) we get

b+c+c+a-a-b=10w-5w

2c=5w or c=5w/2

So No of days taken by c to complete the remaing 30w work

=30w/(5w/2)=30w/1*2/5w==12 days