Container J contains 3 pink marbles and 15 blue marbles. Container K contains 39 pink marbles and 11 blue marbles. How many blue marbles and pink marbles must be transferred from Container K to put into Container J so that 50% of the marbles in Container A are pink and 75% of the marbles in Container K are pink?

	Container J		Container K
	Pink marbles	Blue marbles	Pink marbles	Blue marbles
Before	3	15	39	11
Change	+ ?	+ ?	- ?	- ?
After	1 u	1 u	3 p	1 p

50% = ⁵⁰₁₀₀ = 12

75% = ⁷⁵₁₀₀ = 34

Number of pink marbles = 3 + 39 = 42 

Number of blue marbles = 15 + 11 = 26 

1 u + 3 p = 42 --- (1)

1 u + 1 p = 26 ---(2)

(1) - (2)
(1 u + 3 p) - (1 u + 1 p) = 42 - 26
3 p - 1 p = 16
2 p = 16

1 p = 16 ÷ 2 = 8

From (2):
1 u + 1 p = 26
1 u + 1 x 8 = 26
1 u + 8 = 26

1 u = 26 - 8 = 18

Number of blue marbles to be transferred from Container K to Container J
= 11 - 1 p
= 11 - 1 x 8
= 11 - 8
= 3

Number of pink marbles to be transferred from Container K to Container J
= 1 u - 3
= 18 - 3
= 15

Total number of blue and pink marbles to be transferred from Container K to Container J
= 3 + 15
= 18

Answer(s): 18