The ratio of the number of red stickers to green stickers is 3 : 2.
After Adam gives away 97 red stickers and gives away 53 green stickers,
the ratio becomes of the number of red stickers to green stickers is 7 : 3.
How many stickers does Adam have now?
|
Make p the same (1) x 3 = (3) |
(1) Red |
(2) Green |
Make p the same (2) x 7 = (4) |
Before |
9 u |
3 u |
2 u |
14 u |
Change |
- 291 |
- 97 |
- 53 |
- 371 |
After |
21 p |
7 p |
3 p |
21 p |
3 u - 97 = 7 p --- (1)
2 u - 53 = 3 p --- (2)
Make p the same.
(1) x 3
9 u - 291 = 21 p --- (3)
(2) x 7
14 u - 371 = 21 p --- (4)
(4) = (3)
14 u - 371 = 9 u - 291
14 u - 9 u = 371 - 291
5 u = 80
1 u = 80 ÷ 5 = 16
Number of stickers that Adam has now
= 3 u - 97 + 2 u - 53
= 5 u - 150
= 5 x 16 - 150
= 80 - 150
= -70
Answer(s): -70