The ratio of the number of blue stickers to green stickers is 3 : 2.
After Adam gives away 99 blue stickers and gives away 51 green stickers,
the ratio becomes of the number of blue stickers to green stickers is 7 : 3.
How many stickers does Adam have now?
|
Make p the same (1) x 3 = (3) |
(1) Blue |
(2) Green |
Make p the same (2) x 7 = (4) |
Before |
9 u |
3 u |
2 u |
14 u |
Change |
- 297 |
- 99 |
- 51 |
- 357 |
After |
21 p |
7 p |
3 p |
21 p |
3 u - 99 = 7 p --- (1)
2 u - 51 = 3 p --- (2)
Make p the same.
(1) x 3
9 u - 297 = 21 p --- (3)
(2) x 7
14 u - 357 = 21 p --- (4)
(4) = (3)
14 u - 357 = 9 u - 297
14 u - 9 u = 357 - 297
5 u = 60
1 u = 60 ÷ 5 = 12
Number of stickers that Adam has now
= 3 u - 99 + 2 u - 51
= 5 u - 150
= 5 x 12 - 150
= 60 - 150
= -90
Answer(s): -90