Adam has red and green stickers in the ratio of 9 : 7.
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 = 9 u
Number of green stickers = 7 u
Number of more red stickers than green stickers
= 9 u - 7 u
= 2 u
2 u = 40
1 u = 40 ÷ 2 = 20
Number of stickers that Adam has
= 9 u + 7 u
= 16 u
= 16 x 20
= 320
(b)
Number of red stickers after Adam gives away 20
= 9 u - 20
= 9 x 20 - 20
= 180 - 20
= 160
Number of green stickers
= 7 u
= 7 x 20
= 140
New ratio of the number of red stickers to green stickers
160 : 140
(÷ 20) 8 : 7
Answer(s): (a) 320; (b) 8 : 7