There were some red stickers and pink stickers. The stickers were packed into 2 bags. At first, Bag Q contained 120 stickers and 40% of them were pink stickers. Bag R contained 250 stickers and 60% of them were pink stickers. How many red stickers and pink stickers in total must be moved from Bag Q to Bag R such that 25% of the stickers in Bag Q are red and 50% of the stickers in Bag R are pink?

	Bag Q		Bag R
Total	120		250
	Pink stickers	Red stickers	Pink stickers	Red stickers
Before	48	72	150	100
Change	- ?	- ?	+ ?	+ ?
After	3 u	1 u	1 p	1 p

Number of pink stickers in Bag Q at first
= 40% x 120
= ⁴⁰₁₀₀ x 120
= 48

Number of red stickers in Bag Q at first
= 120 - 48
= 72

Number of pink stickers in Bag R at first
= 60% x 250
= ⁶⁰₁₀₀ x 250
= 150

Number of red stickers in Bag R at first
= 250 - 150
= 100

Bag Q in the end
25% = ²⁵₁₀₀ =¹₄
Pink stickers : Red stickers = 3 : 1

Bag R in the end
50% = ⁵⁰₁₀₀ =¹₂
Pink stickers : Red stickers = 1 : 1

Total number of pink stickers = 3 u + 1 p

3 u + 1 p = 48 + 150
3 u + 1 p = 198 

1 p = 198 - 3 u --- (1)

Total number of red stickers = 1 u + 1 p
1 u + 1 p = 72 + 100
1 u + 1 p = 172

1 p = 172 - 1 u --- (2)

(2) = (1)
172 - 1 u = 198 - 3 u
3 u - 1 u = 198 - 172
2 u = 26

1 u = 26 ÷ 2 = 13

Total number of red stickers and pink stickers that must be moved from Bag Q to Bag R
= 120 - 4 u
= 120 - 4 x 13
= 120 - 52
= 68

Answer(s): 68