The ratio of the number of blue stickers to green stickers is 5 : 2.
After Adam gives away 85 blue stickers and gives away 82 green stickers,
the ratio becomes of the number of blue stickers to green stickers is 7 : 2.
How many stickers does Adam have now?
|
Make p the same (1) x 2 = (3) |
(1) Blue |
(2) Green |
Make p the same (2) x 7 = (4) |
Before |
10 u |
5 u |
2 u |
14 u |
Change |
- 170 |
- 85 |
- 82 |
- 574 |
After |
14 p |
7 p |
2 p |
14 p |
5 u - 85 = 7 p --- (1)
2 u - 82 = 2 p --- (2)
Make p the same.
(1) x 2
10 u - 170 = 14 p --- (3)
(2) x 7
14 u - 574 = 14 p --- (4)
(4) = (3)
14 u - 574 = 10 u - 170
14 u - 10 u = 574 - 170
4 u = 404
1 u = 404 ÷ 4 = 101
Number of stickers that Adam has now
= 5 u - 85 + 2 u - 82
= 7 u - 167
= 7 x 101 - 167
= 707 - 167
= 540
Answer(s): 540