Cindy had 350 stickers. ³₇ were green and the rest were pink and brown. The ratio of the number of pink stickers to the number of brown stickers was 1 : 4. Cindy decided to buy some more green stickers to increase the number of green stickers to half of the total number of stickers.

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

Green stickers	Pink stickers	Brown stickers	Total
3x5	4x5
	1x4	4x4
15 u	4 u	16 u	350

	Green stickers	Pink stickers	Brown stickers
Before	15 u	4 u	16 u
Change	+ ?
After	20 u	20 u
Comparing green, pink and brown stickers in the end	1	1

(a)
The total number of pink stickers and brown stickers is repeated. Make the total number of pink stickers and brown stickers the same.  LCM of 4 and 5 is 20.

Total number of stickers at first
= 15 u + 4 u + 16 u
= 35 u

35 u = 350

1 u = 350 ÷ 35 = 10

Number of less pink stickers than green stickers at first
= 15 u - 4 u
= 11 u
= 11 x 10
= 110

(b)
Number of more green stickers that Cindy had to buy
= 20 u - 15 u
= 5 u
= 5 x 10
= 50

Answer(s): (a) 110; (b) 50