The ratio of the number of red stickers to green stickers is 4 : 3.
After Adam gives away 29 red stickers and gives away 87 green stickers,
the ratio becomes of the number of red stickers to green stickers is 5 : 3.
How many stickers does Adam have now?
|
Make p the same (1) x 3 = (3) |
(1) Red |
(2) Green |
Make p the same (2) x 5 = (4) |
Before |
12 u |
4 u |
3 u |
15 u |
Change |
- 87 |
- 29 |
- 87 |
- 435 |
After |
15 p |
5 p |
3 p |
15 p |
4 u - 29 = 5 p --- (1)
3 u - 87 = 3 p --- (2)
Make p the same.
(1) x 3
12 u - 87 = 15 p --- (3)
(2) x 5
15 u - 435 = 15 p --- (4)
(4) = (3)
15 u - 435 = 12 u - 87
15 u - 12 u = 435 - 87
3 u = 348
1 u = 348 ÷ 3 = 116
Number of stickers that Adam has now
= 4 u - 29 + 3 u - 87
= 7 u - 116
= 7 x 116 - 116
= 812 - 116
= 696
Answer(s): 696