Adam has some blue stickers and red stickers.
If Adam gives away 36 blue stickers,
the blue stickers will be 25% as many as the red stickers.
If Adam gives away 21 red stickers,
the blue stickers will be 80% as many as the red stickers.

1. How many blue stickers are there? 
2. How many red stickers are there? 

	Scenario 1		Scenario 2
	Blue	Red	Blue	Red
Before	1 u + 36	4 u	4 p	5 p + 21
Change	- 36	No change	No change	- 21
After	1 u	4 u	4 p	5 p

(a)
25% = ²⁵₁₀₀ = ¹₄
80% = ⁸⁰₁₀₀ = ⁴₅

Scenario 1
Number of blue stickers at first = 1 u + 36
Number of red stickers at first = 4 u

Scenario 2
Number of blue stickers at first = 4 p
Number of red stickers at first = 5 p + 21

1 u + 36 = 4 p --- (1)
4 u = 5 p + 21 --- (2)

(1) _{x 4}
4 u + 144 = 16 p
4 u = 16 p - 144 --- (3)

(3) = (2)
16 p - 144 = 5 p + 21
16 p - 5 p = 144 + 21
11 p = 165

1 p = 165 ÷ 11 = 15

Number of blue stickers
= 4 p
= 4 x 15
= 60

(b)
Number of red stickers at first
= 5 p + 21
= 5 x 15 + 21
= 75 + 21
= 96

Answer(s): (a) 60; (b) 96