A,B&C can finish a job in 10 days, A and B in 12 days and A&C in 20 days. How many days before they finish the job alone?
SOME ONE CAN GIVE ME A CORRECT SOLUTIONS?
Answers:
A = 30
B = 10
C = 60

Use rate formulae.

Amount of work done = Rate of work x Time

Let the rate of A be a, the rate of b be b and the rate of c be c. Let the total work to be done be w.

In the first case, you get:

w = 10a + 10b + 10c

In the second case you get:

w = 12a + 12b

In the third case you get:

w = 20a + 20c

You can equate all of them: 10a + 10b + 10c = 12a + 12b = 20a + 20c

Then solve for a, b and c.

YEAH I got It ^_^ Thank you so much...

You're welcome! :)