There are some green and silver balls in a container. If 10 green balls are removed from the container, the total number of balls left will be 9 times the number of green balls left. If 25 silver balls are removed from the container, the total number of balls left will be 4 times the number of green balls. How many balls are there in the container?

	Case 1		Case 2
	Green balls	Silver balls	Green balls	Silver balls
Before	1 u + 10	8 u	1 p	3 p + 25
Change	- 10			- 25
After	1 u	8 u	1 p	3 p

Number of silver balls in the end for Case 1
= 9 u - 1 u
= 8 u

Number of green balls in the end for Case 2
= 4 p - 1 p
= 3 p

The number of green balls at first is the same for Case 1 and Case 2.
The number of silver balls at first is also the same for Case 1 and Case 2.

1 u + 10 = 1 p --- (1)

8 u = 3 p + 25
8 u - 25 = 3 p --- (2)

Make p the same.

(1)_x3
3 u + 30 = 3 p --- (3)

(2) = (3)
8 u - 25 = 3 u + 30
8 u - 3 u = 30 + 25
5 u = 55

1 u = 55 ÷ 5 = 11

Number of balls in the container
= (1 u + 10) + 8 u
= 9 u + 10
= (9 x 11) + 10
= 99 + 10
= 109

Answer(s): 109