Container U contains 10 green balls and 12 yellow balls. Container V contains 15 green balls and 7 yellow balls. How many yellow balls and green balls must be moved from Container V to put into Container U so that 50% of the balls in Container A are green and 75% of the balls in Container V are green?

	Container U		Container V
	Green balls	Yellow balls	Green balls	Yellow balls
Before	10	12	15	7
Change	+ ?	+ ?	- ?	- ?
After	1 u	1 u	3 p	1 p

50% = ⁵⁰₁₀₀ = 12

75% = ⁷⁵₁₀₀ = 34

Number of green balls = 10 + 15 = 25 

Number of yellow balls = 12 + 7 = 19 

1 u + 3 p = 25 --- (1)

1 u + 1 p = 19 ---(2)

(1) - (2)
(1 u + 3 p) - (1 u + 1 p) = 25 - 19
3 p - 1 p = 6
2 p = 6

1 p = 6 ÷ 2 = 3

From (2):
1 u + 1 p = 19
1 u + 1 x 3 = 19
1 u + 3 = 19

1 u = 19 - 3 = 16

Number of yellow balls to be moved from Container V to Container U
= 7 - 1 p
= 7 - 1 x 3
= 7 - 3
= 4

Number of green balls to be moved from Container V to Container U
= 1 u - 10
= 16 - 10
= 6

Total number of yellow and green balls to be moved from Container V to Container U
= 4 + 6
= 10

Answer(s): 10