8 days ago, Erika had a total of 250 silver and blue stickers. 20% of her stickers were blue stickers. Today, her older brother gave her some more stickers. As a result, her silver stickers increased by 40%. Now, 50% of her stickers are blue stickers. How many blue stickers did her older brother give her?

	Blue stickers	Silver stickers	Total  stickers
Before	1 u	4 u	250
Change	+ 4.6 u	+ 1.6 u
After	5.6 u	5.6 u
Comparing the silver stickers and blue stickers in the end	1	1

20% = ²⁰₁₀₀ = ¹₅

Blue stickers : Silver stickers = 1 : 4

Increase in the number of silver stickers
= 40% x 4 u
= ⁴⁰₁₀₀ x 4 u
= 1.6 u

50% = ⁵⁰₁₀₀ = ¹₂

In the end
Blue stickers : Silver stickers = 1 : 1

Number of stickers at first
= 4 u + 1 u
= 5 u 

5 u = 250

1 u = 250 ÷ 5 = 50

Number of blue stickers that Erika received from her older brother
= 5.6 u - 1 u
= 4.6 u
= 4.6 x 50
= 230

Answer(s): 230