There were some pink stamps and green stamps. The stamps were packed into 2 bags. At first, Box X contained 230 stamps and 30% of them were green stamps. Box Y contained 600 stamps and 60% of them were green stamps. How many pink stamps and green stamps in total must be moved from Box X to Box Y such that 25% of the stamps in Box X are pink and 50% of the stamps in Box Y are green?

	Box X		Box Y
Total	230		600
	Green stamps	Pink stamps	Green stamps	Pink stamps
Before	69	161	360	240
Change	- ?	- ?	+ ?	+ ?
After	3 u	1 u	1 p	1 p

Number of green stamps in Box X at first
= 30% x 230
= ³⁰₁₀₀ x 230
= 69

Number of pink stamps in Box X at first
= 230 - 69
= 161

Number of green stamps in Box Y at first
= 60% x 600
= ⁶⁰₁₀₀ x 600
= 360

Number of pink stamps in Box Y at first
= 600 - 360
= 240

Box X in the end
25% = ²⁵₁₀₀ =¹₄
Green stamps : Pink stamps = 3 : 1

Box Y in the end
50% = ⁵⁰₁₀₀ =¹₂
Green stamps : Pink stamps = 1 : 1

Total number of green stamps = 3 u + 1 p

3 u + 1 p = 69 + 360
3 u + 1 p = 429 

1 p = 429 - 3 u --- (1)

Total number of pink stamps = 1 u + 1 p
1 u + 1 p = 161 + 240
1 u + 1 p = 401

1 p = 401 - 1 u --- (2)

(2) = (1)
401 - 1 u = 429 - 3 u
3 u - 1 u = 429 - 401
2 u = 28

1 u = 28 ÷ 2 = 14

Total number of pink stamps and green stamps that must be moved from Box X to Box Y
= 230 - 4 u
= 230 - 4 x 14
= 230 - 56
= 174

Answer(s): 174