Crate P contains 6 brown beads and 9 yellow beads. Crate Q contains 21 brown beads and 10 yellow beads. How many yellow beads and brown beads must be removed from Crate Q to put into Crate P so that 50% of the beads in Crate A are brown and 75% of the beads in Crate Q are brown?

	Crate P		Crate Q
	Brown beads	Yellow beads	Brown beads	Yellow beads
Before	6	9	21	10
Change	+ ?	+ ?	- ?	- ?
After	1 u	1 u	3 p	1 p

50% = ⁵⁰₁₀₀ = 12

75% = ⁷⁵₁₀₀ = 34

Number of brown beads = 6 + 21 = 27 

Number of yellow beads = 9 + 10 = 19 

1 u + 3 p = 27 --- (1)

1 u + 1 p = 19 ---(2)

(1) - (2)
(1 u + 3 p) - (1 u + 1 p) = 27 - 19
3 p - 1 p = 8
2 p = 8

1 p = 8 ÷ 2 = 4

From (2):
1 u + 1 p = 19
1 u + 1 x 4 = 19
1 u + 4 = 19

1 u = 19 - 4 = 15

Number of yellow beads to be removed from Crate Q to Crate P
= 10 - 1 p
= 10 - 1 x 4
= 10 - 4
= 6

Number of brown beads to be removed from Crate Q to Crate P
= 1 u - 6
= 15 - 6
= 9

Total number of yellow and brown beads to be removed from Crate Q to Crate P
= 6 + 9
= 15

Answer(s): 15