Box X contains 4 gold beads and 8 white beads. Box Y contains 59 gold beads and 19 white beads. How many white beads and gold beads must be moved from Box Y to put into Box X so that 50% of the beads in Box A are gold and 80% of the beads in Box Y are gold?

	Box X		Box Y
	Gold beads	White beads	Gold beads	White beads
Before	4	8	59	19
Change	+ ?	+ ?	- ?	- ?
After	1 u	1 u	4 p	1 p

50% = ⁵⁰₁₀₀ = 12

80% = ⁸⁰₁₀₀ = 45

Number of gold beads = 4 + 59 = 63 

Number of white beads = 8 + 19 = 27 

1 u + 4 p = 63 --- (1)

1 u + 1 p = 27 ---(2)

(1) - (2)
(1 u + 4 p) - (1 u + 1 p) = 63 - 27
4 p - 1 p = 36
3 p = 36

1 p = 36 ÷ 3 = 12

From (2):
1 u + 1 p = 27
1 u + 1 x 12 = 27
1 u + 12 = 27

1 u = 27 - 12 = 15

Number of white beads to be moved from Box Y to Box X
= 19 - 1 p
= 19 - 1 x 12
= 19 - 12
= 7

Number of gold beads to be moved from Box Y to Box X
= 1 u - 4
= 15 - 4
= 11

Total number of white and gold beads to be moved from Box Y to Box X
= 7 + 11
= 18

Answer(s): 18