vquidor
Jul 17, 2011, 03:21 AM
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
Unknown008
Jul 17, 2011, 03:34 AM
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.
vquidor
Jul 17, 2011, 03:46 AM
YEAH I got It ^_^ Thank you so much...