Crate K contains 4 red beads and 7 blue beads. Crate L contains 129 red beads and 58 blue beads. How many blue beads and red beads must be moved from Crate L to put into Crate K so that 50% of the beads in Crate A are red and 70% of the beads in Crate L are red?

	Crate K		Crate L
	Red beads	Blue beads	Red beads	Blue beads
Before	4	7	129	58
Change	+ ?	+ ?	- ?	- ?
After	1 u	1 u	7 p	3 p

50% = ⁵⁰₁₀₀ = 12

70% = ⁷⁰₁₀₀ = 710

Number of red beads = 4 + 129 = 133 

Number of blue beads = 7 + 58 = 65 

1 u + 7 p = 133 --- (1)

1 u + 3 p = 65 ---(2)

(1) - (2)
(1 u + 7 p) - (1 u + 3 p) = 133 - 65
7 p - 3 p = 68
4 p = 68

1 p = 68 ÷ 4 = 17

From (2):
1 u + 3 p = 65
1 u + 3 x 17 = 65
1 u + 51 = 65

1 u = 65 - 51 = 14

Number of blue beads to be moved from Crate L to Crate K
= 58 - 3 p
= 58 - 3 x 17
= 58 - 51
= 7

Number of red beads to be moved from Crate L to Crate K
= 1 u - 4
= 14 - 4
= 10

Total number of blue and red beads to be moved from Crate L to Crate K
= 7 + 10
= 17

Answer(s): 17