9 days ago, Tina had a total of 300 white and green stickers. 30% of her stickers were green stickers. Today, her younger sister gave her some more stickers. As a result, her white stickers increased by 40%. Now, 50% of her stickers are green stickers. How many green stickers did her younger sister give her?

	Green stickers	White stickers	Total  stickers
Before	3 u	7 u	300
Change	+ 6.8 u	+ 2.8 u
After	9.8 u	9.8 u
Comparing the white stickers and green stickers in the end	1	1

30% = ³⁰₁₀₀ = ³₁₀

Green stickers : White stickers = 3 : 7

Increase in the number of white stickers
= 40% x 7 u
= ⁴⁰₁₀₀ x 7 u
= 2.8 u

50% = ⁵⁰₁₀₀ = ¹₂

In the end
Green stickers : White stickers = 1 : 1

Number of stickers at first
= 7 u + 3 u
= 10 u 

10 u = 300

1 u = 300 ÷ 10 = 30

Number of green stickers that Tina received from her younger sister
= 9.8 u - 3 u
= 6.8 u
= 6.8 x 30
= 204

Answer(s): 204