There were some silver stamps and pink stamps. The stamps were packed into 2 bags. At first, Bag E contained 280 stamps and 30% of them were pink stamps. Bag F contained 260 stamps and 75% of them were pink stamps. How many silver stamps and pink stamps in total must be moved from Bag E to Bag F such that 25% of the stamps in Bag E are silver and 50% of the stamps in Bag F are pink?

	Bag E		Bag F
Total	280		260
	Pink stamps	Silver stamps	Pink stamps	Silver stamps
Before	84	196	195	65
Change	- ?	- ?	+ ?	+ ?
After	3 u	1 u	1 p	1 p

Number of pink stamps in Bag E at first
= 30% x 280
= ³⁰₁₀₀ x 280
= 84

Number of silver stamps in Bag E at first
= 280 - 84
= 196

Number of pink stamps in Bag F at first
= 75% x 260
= ⁷⁵₁₀₀ x 260
= 195

Number of silver stamps in Bag F at first
= 260 - 195
= 65

Bag E in the end
25% = ²⁵₁₀₀ =¹₄
Pink stamps : Silver stamps = 3 : 1

Bag F in the end
50% = ⁵⁰₁₀₀ =¹₂
Pink stamps : Silver stamps = 1 : 1

Total number of pink stamps = 3 u + 1 p

3 u + 1 p = 84 + 195
3 u + 1 p = 279 

1 p = 279 - 3 u --- (1)

Total number of silver stamps = 1 u + 1 p
1 u + 1 p = 196 + 65
1 u + 1 p = 261

1 p = 261 - 1 u --- (2)

(2) = (1)
261 - 1 u = 279 - 3 u
3 u - 1 u = 279 - 261
2 u = 18

1 u = 18 ÷ 2 = 9

Total number of silver stamps and pink stamps that must be moved from Bag E to Bag F
= 280 - 4 u
= 280 - 4 x 9
= 280 - 36
= 244

Answer(s): 244