The ratio of the number of red stickers to green stickers is 3 : 2.
After Adam gives away 39 red stickers and gives away 84 green stickers,
the ratio becomes of the number of red stickers to green stickers is 7 : 4.
How many stickers does Adam have now?
|
Make p the same (1) x 4 = (3) |
(1) Red |
(2) Green |
Make p the same (2) x 7 = (4) |
Before |
12 u |
3 u |
2 u |
14 u |
Change |
- 156 |
- 39 |
- 84 |
- 588 |
After |
28 p |
7 p |
4 p |
28 p |
3 u - 39 = 7 p --- (1)
2 u - 84 = 4 p --- (2)
Make p the same.
(1) x 4
12 u - 156 = 28 p --- (3)
(2) x 7
14 u - 588 = 28 p --- (4)
(4) = (3)
14 u - 588 = 12 u - 156
14 u - 12 u = 588 - 156
2 u = 432
1 u = 432 ÷ 2 = 216
Number of stickers that Adam has now
= 3 u - 39 + 2 u - 84
= 5 u - 123
= 5 x 216 - 123
= 1080 - 123
= 957
Answer(s): 957