The ratio of the number of blue stickers to green stickers is 3 : 2.
After Adam gives away 12 blue stickers and gives away 23 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 |
- 36 |
- 12 |
- 23 |
- 161 |
After |
21 p |
7 p |
3 p |
21 p |
3 u - 12 = 7 p --- (1)
2 u - 23 = 3 p --- (2)
Make p the same.
(1) x 3
9 u - 36 = 21 p --- (3)
(2) x 7
14 u - 161 = 21 p --- (4)
(4) = (3)
14 u - 161 = 9 u - 36
14 u - 9 u = 161 - 36
5 u = 125
1 u = 125 ÷ 5 = 25
Number of stickers that Adam has now
= 3 u - 12 + 2 u - 23
= 5 u - 35
= 5 x 25 - 35
= 125 - 35
= 90
Answer(s): 90