Question

There are in all, 10 balls; some of them are red and the others white. The average cost of all balls is Rs. 28. If the av erage
cost of red ball is Rs. 25 and that of white balls is Rs. 30, the number of white balls is:

Answer 1

Answer:

There are in all, 10 balls; some of them are red and the others white. The average cost of all balls is Rs. 28. If the av erage

cost of red ball is Rs. 25 and that of white balls is Rs. 30, the number of white balls is:

anwer : 6

Answer 2

By using alligation method(method in attachment)

∴ 5 units -> 10 balls

1 unit -> 2 balls

3 units -> 2×3 = 6 balls

∴ White balls = 6 balls.