There were some pink erasers and yellow erasers. The erasers were packed into 2 bags. At first, Bag N contained 290 erasers and 30% of them were yellow erasers. Bag P contained 740 erasers and 60% of them were yellow erasers. How many pink erasers and yellow erasers in total must be moved from Bag N to Bag P such that 30% of the erasers in Bag N are pink and 50% of the erasers in Bag P are yellow?

	Bag N		Bag P
Total	290		740
	Yellow erasers	Pink erasers	Yellow erasers	Pink erasers
Before	87	203	444	296
Change	- ?	- ?	+ ?	+ ?
After	7 u	3 u	1 p	1 p

Number of yellow erasers in Bag N at first
= 30% x 290
= ³⁰₁₀₀ x 290
= 87

Number of pink erasers in Bag N at first
= 290 - 87
= 203

Number of yellow erasers in Bag P at first
= 60% x 740
= ⁶⁰₁₀₀ x 740
= 444

Number of pink erasers in Bag P at first
= 740 - 444
= 296

Bag N in the end
30% = ³⁰₁₀₀ =³₁₀
Yellow erasers : Pink erasers = 7 : 3

Bag P in the end
50% = ⁵⁰₁₀₀ =¹₂
Yellow erasers : Pink erasers = 1 : 1

Total number of yellow erasers = 7 u + 1 p

7 u + 1 p = 87 + 444
7 u + 1 p = 531 

1 p = 531 - 7 u --- (1)

Total number of pink erasers = 3 u + 1 p
3 u + 1 p = 203 + 296
3 u + 1 p = 499

1 p = 499 - 3 u --- (2)

(2) = (1)
499 - 3 u = 531 - 7 u
7 u - 3 u = 531 - 499
4 u = 32

1 u = 32 ÷ 4 = 8

Total number of pink erasers and yellow erasers that must be moved from Bag N to Bag P
= 290 - 10 u
= 290 - 10 x 8
= 290 - 80
= 210

Answer(s): 210