The ratio of the number of green stickers to red stickers is 8 : 3.
After Adam gives away 85 green stickers and gives away 100 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 |
- 170 |
- 85 |
- 100 |
- 700 |
After |
14 p |
7 p |
2 p |
14 p |
8 u - 85 = 7 p --- (1)
3 u - 100 = 2 p --- (2)
Make p the same.
(1) x 2
16 u - 170 = 14 p --- (3)
(2) x 7
21 u - 700 = 14 p --- (4)
(4) = (3)
21 u - 700 = 16 u - 170
21 u - 16 u = 700 - 170
5 u = 530
1 u = 530 ÷ 5 = 106
Number of stickers that Adam has now
= 8 u - 85 + 3 u - 100
= 11 u - 185
= 11 x 106 - 185
= 1166 - 185
= 981
Answer(s): 981