Irene had 224 stickers. ²₇ were white and the rest were green and red. The ratio of the number of green stickers to the number of red stickers was 1 : 3. Irene decided to buy some more white stickers to increase the number of white stickers to half of the total number of stickers.

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

White stickers	Green stickers	Red stickers	Total
2x4	5x4
	1x5	3x5
8 u	5 u	15 u	224

	White stickers	Green stickers	Red stickers
Before	8 u	5 u	15 u
Change	+ ?
After	20 u	20 u
Comparing white, green and red stickers in the end	1	1

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

Total number of stickers at first
= 8 u + 5 u + 15 u
= 28 u

28 u = 224

1 u = 224 ÷ 28 = 8

Number of less green stickers than white stickers at first
= 8 u - 5 u
= 3 u
= 3 x 8
= 24

(b)
Number of more white stickers that Irene had to buy
= 20 u - 8 u
= 12 u
= 12 x 8
= 96

Answer(s): (a) 24; (b) 96