The ratio of the number of green stickers to red stickers is 8 : 3.
After Adam buys another 39 red stickers and gives away 28 green stickers,
the ratio becomes of the number of green stickers to red stickers is 4 : 3.
How many stickers does Adam have now?
|
Make p the same (1) x 3 = (3) |
(1) Green |
(2) Red |
Make p the same (2) x 4 = (4) |
Before |
24 u |
8 u |
3 u |
12 u |
Change |
- 84 |
- 28 |
+ 39 |
+ 156 |
After |
12 p |
4 p |
3 p |
12 p |
8 u + 39 = 4 p --- (1)
3 u - 28 = 3 p --- (2)
Make p the same.
(1)
x 324 u - 84 = 12 p --- (3)
(2)
x 412 u + 156 = 12 p --- (4)
(3) = (4)
24 u - 84 = 12 u + 156
24 u - 12 u = 84 + 156
12 u = 240
1 u = 240 ÷ 12 = 20
Number of stickers that Adam have now
= 8 u + 39 + 3 u - 28
= 8 u + 3 u + 39 - 28
= 11 u + 11
= 11 x 20 + 11
= 220 + 11
= 231
Answer(s): 231