Crate D contains 4 black beads and 13 pink beads. Crate E contains 70 black beads and 23 pink beads. How many pink beads and black beads must be moved from Crate E to put into Crate D so that 50% of the beads in Crate A are black and 75% of the beads in Crate E are black?

	Crate D		Crate E
	Black beads	Pink beads	Black beads	Pink beads
Before	4	13	70	23
Change	+ ?	+ ?	- ?	- ?
After	1 u	1 u	3 p	1 p

50% = ⁵⁰₁₀₀ = 12

75% = ⁷⁵₁₀₀ = 34

Number of black beads = 4 + 70 = 74 

Number of pink beads = 13 + 23 = 36 

1 u + 3 p = 74 --- (1)

1 u + 1 p = 36 ---(2)

(1) - (2)
(1 u + 3 p) - (1 u + 1 p) = 74 - 36
3 p - 1 p = 38
2 p = 38

1 p = 38 ÷ 2 = 19

From (2):
1 u + 1 p = 36
1 u + 1 x 19 = 36
1 u + 19 = 36

1 u = 36 - 19 = 17

Number of pink beads to be moved from Crate E to Crate D
= 23 - 1 p
= 23 - 1 x 19
= 23 - 19
= 4

Number of black beads to be moved from Crate E to Crate D
= 1 u - 4
= 17 - 4
= 13

Total number of pink and black beads to be moved from Crate E to Crate D
= 4 + 13
= 17

Answer(s): 17