The ratio of the number of green stickers to red stickers is 3 : 2.
After Adam buys another 24 red stickers and gives away 12 green stickers,
the ratio becomes of the number of green stickers to red stickers is 5 : 4.
How many stickers does Adam have now?
|
Make p the same (1) x 4 = (3) |
(1) Green |
(2) Red |
Make p the same (2) x 5 = (4) |
Before |
12 u |
3 u |
2 u |
10 u |
Change |
- 48 |
- 12 |
+ 24 |
+ 120 |
After |
20 p |
5 p |
4 p |
20 p |
3 u + 24 = 5 p --- (1)
2 u - 12 = 4 p --- (2)
Make p the same.
(1)
x 412 u - 48 = 20 p --- (3)
(2)
x 510 u + 120 = 20 p --- (4)
(3) = (4)
12 u - 48 = 10 u + 120
12 u - 10 u = 48 + 120
2 u = 168
1 u = 168 ÷ 2 = 84
Number of stickers that Adam have now
= 3 u + 24 + 2 u - 12
= 3 u + 2 u + 24 - 12
= 5 u + 12
= 5 x 84 + 12
= 420 + 12
= 432
Answer(s): 432