The ratio of the number of green stickers to red stickers is 7 : 3.
After Adam buys another 28 red stickers and gives away 18 green stickers,
the ratio becomes of the number of green stickers to red stickers is 3 : 2.
How many stickers does Adam have now?
|
Make p the same (1) x 2 = (3) |
(1) Green |
(2) Red |
Make p the same (2) x 3 = (4) |
Before |
14 u |
7 u |
3 u |
9 u |
Change |
- 36 |
- 18 |
+ 28 |
+ 84 |
After |
6 p |
3 p |
2 p |
6 p |
7 u + 28 = 3 p --- (1)
3 u - 18 = 2 p --- (2)
Make p the same.
(1)
x 214 u - 36 = 6 p --- (3)
(2)
x 39 u + 84 = 6 p --- (4)
(3) = (4)
14 u - 36 = 9 u + 84
14 u - 9 u = 36 + 84
5 u = 120
1 u = 120 ÷ 5 = 24
Number of stickers that Adam have now
= 7 u + 28 + 3 u - 18
= 7 u + 3 u + 28 - 18
= 10 u + 10
= 10 x 24 + 10
= 240 + 10
= 250
Answer(s): 250