Box J contains 3 white beads and 8 blue beads. Box K contains 18 white beads and 7 blue beads. How many blue beads and white beads must be moved from Box K to put into Box J so that 50% of the beads in Box A are white and 75% of the beads in Box K are white?

	Box J		Box K
	White beads	Blue beads	White beads	Blue beads
Before	3	8	18	7
Change	+ ?	+ ?	- ?	- ?
After	1 u	1 u	3 p	1 p

50% = ⁵⁰₁₀₀ = 12

75% = ⁷⁵₁₀₀ = 34

Number of white beads = 3 + 18 = 21 

Number of blue beads = 8 + 7 = 15 

1 u + 3 p = 21 --- (1)

1 u + 1 p = 15 ---(2)

(1) - (2)
(1 u + 3 p) - (1 u + 1 p) = 21 - 15
3 p - 1 p = 6
2 p = 6

1 p = 6 ÷ 2 = 3

From (2):
1 u + 1 p = 15
1 u + 1 x 3 = 15
1 u + 3 = 15

1 u = 15 - 3 = 12

Number of blue beads to be moved from Box K to Box J
= 7 - 1 p
= 7 - 1 x 3
= 7 - 3
= 4

Number of white beads to be moved from Box K to Box J
= 1 u - 3
= 12 - 3
= 9

Total number of blue and white beads to be moved from Box K to Box J
= 4 + 9
= 13

Answer(s): 13