The ratio of the number of green stickers to red stickers is 8 : 3.
After Adam gives away 74 green stickers and gives away 29 red stickers,
the ratio becomes of the number of green stickers to red stickers is 7 : 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 7 = (4) |
Before |
16 u |
8 u |
3 u |
21 u |
Change |
- 148 |
- 74 |
- 29 |
- 203 |
After |
14 p |
7 p |
2 p |
14 p |
8 u - 74 = 7 p --- (1)
3 u - 29 = 2 p --- (2)
Make p the same.
(1) x 2
16 u - 148 = 14 p --- (3)
(2) x 7
21 u - 203 = 14 p --- (4)
(4) = (3)
21 u - 203 = 16 u - 148
21 u - 16 u = 203 - 148
5 u = 55
1 u = 55 ÷ 5 = 11
Number of stickers that Adam has now
= 8 u - 74 + 3 u - 29
= 11 u - 103
= 11 x 11 - 103
= 121 - 103
= 18
Answer(s): 18