There were some silver stickers and white stickers. The stickers were packed into 2 bags. At first, Packet P contained 250 stickers and 30% of them were white stickers. Packet Q contained 210 stickers and 80% of them were white stickers. How many silver stickers and white stickers in total must be moved from Packet P to Packet Q such that 25% of the stickers in Packet P are silver and 50% of the stickers in Packet Q are white?

	Packet P		Packet Q
Total	250		210
	White stickers	Silver stickers	White stickers	Silver stickers
Before	75	175	168	42
Change	- ?	- ?	+ ?	+ ?
After	3 u	1 u	1 p	1 p

Number of white stickers in Packet P at first
= 30% x 250
= ³⁰₁₀₀ x 250
= 75

Number of silver stickers in Packet P at first
= 250 - 75
= 175

Number of white stickers in Packet Q at first
= 80% x 210
= ⁸⁰₁₀₀ x 210
= 168

Number of silver stickers in Packet Q at first
= 210 - 168
= 42

Packet P in the end
25% = ²⁵₁₀₀ =¹₄
White stickers : Silver stickers = 3 : 1

Packet Q in the end
50% = ⁵⁰₁₀₀ =¹₂
White stickers : Silver stickers = 1 : 1

Total number of white stickers = 3 u + 1 p

3 u + 1 p = 75 + 168
3 u + 1 p = 243 

1 p = 243 - 3 u --- (1)

Total number of silver stickers = 1 u + 1 p
1 u + 1 p = 175 + 42
1 u + 1 p = 217

1 p = 217 - 1 u --- (2)

(2) = (1)
217 - 1 u = 243 - 3 u
3 u - 1 u = 243 - 217
2 u = 26

1 u = 26 ÷ 2 = 13

Total number of silver stickers and white stickers that must be moved from Packet P to Packet Q
= 250 - 4 u
= 250 - 4 x 13
= 250 - 52
= 198

Answer(s): 198