Working together, printer A and printer B would finish the task in 24 minutes. Printer

Working together, printer A and printer B would finish the task in 24 minutes. Printer A alone would finish the task in 60 minutes. How many pages does the task contain if printer B prints 5 pages a minute more than printer A ?
1:600
2:800
3:1000
4:1200
5:1500








Soln: Printer A alone finishes the task in 60 mins Hence work done in 1 min is (1/60)
Let printer B alone finish the task in B mins. Hence work done in 1 min is (1/B)
Together they finish in 24 mins. Hence work done in 1 min is (1/24)

Now, we get equation,
(1/60) + (1/B) = (1/24)
Solving, we get B = 40 mins.

Number of papers that A prints per minute be = X
Hence number of papers that B prints per minute be = (X + 5)

Total papers printer in 24 mins will be
= 24X + 24(X+5) - eq(1)

If A were to work alone it will finish task in 60 mins. Hence papers printed in 60 mins will be
= 60X - eq(2)

Equating eq(1) & eq(2) we get,
24X + 24(X+5) = 60X

Solving for X, we get X = 10.

Hence the task contains 60X pages to be printed = 60 * 10 = 600 pages.
Ans: 1