Jean had 252 stickers. ³₇ were blue and the rest were brown and red. The ratio of the number of brown stickers to the number of red stickers was 1 : 2. Jean decided to buy some more blue stickers to increase the number of blue stickers to half of the total number of stickers.

1. How many less brown stickers than blue stickers did he have at first?
2. How many more blue stickers did he have to buy?

Blue stickers	Brown stickers	Red stickers	Total
3x3	4x3
	1x4	2x4
9 u	4 u	8 u	252

	Blue stickers	Brown stickers	Red stickers
Before	9 u	4 u	8 u
Change	+ ?
After	12 u	12 u
Comparing blue, brown and red stickers in the end	1	1

(a)
The total number of brown stickers and red stickers is repeated. Make the total number of brown stickers and red stickers the same.  LCM of 4 and 3 is 12.

Total number of stickers at first
= 9 u + 4 u + 8 u
= 21 u

21 u = 252

1 u = 252 ÷ 21 = 12

Number of less brown stickers than blue stickers at first
= 9 u - 4 u
= 5 u
= 5 x 12
= 60

(b)
Number of more blue stickers that Jean had to buy
= 12 u - 9 u
= 3 u
= 3 x 12
= 36

Answer(s): (a) 60; (b) 36