Adam has red and green stickers in the ratio of 7 : 2.
He has 40 more red stickers than green stickers.
- How many stickers does Adam have?
- If Adam gives away 20 red stickers, what is the new ratio of the number of red stickers to green stickers?
(a)
Number of red stickers = 7 u
Number of green stickers = 2 u
Number of more red stickers than green stickers
= 7 u - 2 u
= 5 u
5 u = 40
1 u = 40 ÷ 5 = 8
Number of stickers that Adam has
= 7 u + 2 u
= 9 u
= 9 x 8
= 72
(b)
Number of red stickers after Adam gives away 20
= 7 u - 20
= 7 x 8 - 20
= 56 - 20
= 36
Number of green stickers
= 2 u
= 2 x 20
= 16
New ratio of the number of red stickers to green stickers
36 : 16
(÷ 4) 9 : 4
Answer(s): (a) 72; (b) 9 : 4