The ratio of the number of blue stickers to green stickers is 7 : 2.
After Adam gives away 30 blue stickers and gives away 28 green stickers,
the ratio becomes of the number of blue stickers to green stickers is 9 : 2.
How many stickers does Adam have now?
|
Make p the same (1) x 2 = (3) |
(1) Blue |
(2) Green |
Make p the same (2) x 9 = (4) |
Before |
14 u |
7 u |
2 u |
18 u |
Change |
- 60 |
- 30 |
- 28 |
- 252 |
After |
18 p |
9 p |
2 p |
18 p |
7 u - 30 = 9 p --- (1)
2 u - 28 = 2 p --- (2)
Make p the same.
(1) x 2
14 u - 60 = 18 p --- (3)
(2) x 9
18 u - 252 = 18 p --- (4)
(4) = (3)
18 u - 252 = 14 u - 60
18 u - 14 u = 252 - 60
4 u = 192
1 u = 192 ÷ 4 = 48
Number of stickers that Adam has now
= 7 u - 30 + 2 u - 28
= 9 u - 58
= 9 x 48 - 58
= 432 - 58
= 374
Answer(s): 374