If 197 blue stickers are added, 40% of the stickers will be green stickers.
If 202 green stickers are added, 20% of the stickers will be blue stickers.

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

	Scenario 1		Scenario 2
	Blue	Green	Blue	Green
Before	3 u - 197	2 u	1 p	4 p - 202
Change	+ 197	No change	No change	+ 202
After	3 u	2 u	1 p	4 p

(a)
40% = ⁴⁰₁₀₀ = ²₅
20% = ²⁰₁₀₀ = ¹₅

Scenario 1
Fraction of the stickers that are blue
= 1 - ²₅
= ³₅

Number of blue stickers at first = 3 u - 197
Number of green stickers at first = 2 u

Scenario 2
Fraction of the stickers that are green
= 1 - ¹₅
= ⁴₅

Number of blue stickers at first = 1 p
Number of green stickers at first = 4 p - 202

3 u - 197 = 1 p --- (1)

2 u = 4 p - 202
2 u + 202 = 4 p --- (2)

(1) _{x 4}
12 u - 788 = 4 p --- (3)

(3) = (2)
12 u - 788 = 2 u + 202
12 u - 2 u = 788 + 202
10 u = 990

1 u = 990 ÷ 10 = 99

Number of blue stickers
= 3 u - 197
= 3 x 99 - 197
= 297 - 197
= 100

(b)
Number of green stickers
= 2 u
= 2 x 99
= 198

Answer(s): (a) 100; (b) 198