There are some green and yellow balls in a container. If 4 green balls are removed from the container, the total number of balls left will be 8 times the number of green balls left. If 14 yellow balls are removed from the container, the total number of balls left will be 5 times the number of green balls. How many balls are there in the container?

	Case 1		Case 2
	Green balls	Yellow balls	Green balls	Yellow balls
Before	1 u + 4	7 u	1 p	4 p + 14
Change	- 4			- 14
After	1 u	7 u	1 p	4 p

Number of yellow balls in the end for Case 1
= 8 u - 1 u
= 7 u

Number of green balls in the end for Case 2
= 5 p - 1 p
= 4 p

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

1 u + 4 = 1 p --- (1)

7 u = 4 p + 14
7 u - 14 = 4 p --- (2)

Make p the same.

(1)_x4
4 u + 16 = 4 p --- (3)

(2) = (3)
7 u - 14 = 4 u + 16
7 u - 4 u = 16 + 14
3 u = 30

1 u = 30 ÷ 3 = 10

Number of balls in the container
= (1 u + 4) + 7 u
= 8 u + 4
= (8 x 10) + 4
= 80 + 4
= 84

Answer(s): 84