Crate P contains 8 red marbles and 5 brown marbles. Crate Q contains 23 red marbles and 17 brown marbles. How many brown marbles and red marbles must be removed from Crate Q to put into Crate P so that 50% of the marbles in Crate A are red and 80% of the marbles in Crate Q are red?

	Crate P		Crate Q
	Red marbles	Brown marbles	Red marbles	Brown marbles
Before	8	5	23	17
Change	+ ?	+ ?	- ?	- ?
After	1 u	1 u	4 p	1 p

50% = ⁵⁰₁₀₀ = 12

80% = ⁸⁰₁₀₀ = 45

Number of red marbles = 8 + 23 = 31 

Number of brown marbles = 5 + 17 = 22 

1 u + 4 p = 31 --- (1)

1 u + 1 p = 22 ---(2)

(1) - (2)
(1 u + 4 p) - (1 u + 1 p) = 31 - 22
4 p - 1 p = 9
3 p = 9

1 p = 9 ÷ 3 = 3

From (2):
1 u + 1 p = 22
1 u + 1 x 3 = 22
1 u + 3 = 22

1 u = 22 - 3 = 19

Number of brown marbles to be removed from Crate Q to Crate P
= 17 - 1 p
= 17 - 1 x 3
= 17 - 3
= 14

Number of red marbles to be removed from Crate Q to Crate P
= 1 u - 8
= 19 - 8
= 11

Total number of brown and red marbles to be removed from Crate Q to Crate P
= 14 + 11
= 25

Answer(s): 25