The ratio of the number of blue stickers to green stickers is 3 : 2.
After Adam gives away 20 blue stickers and gives away 92 green stickers,
the ratio becomes of the number of blue stickers to green stickers is 5 : 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 5 = (4) |
Before |
6 u |
3 u |
2 u |
10 u |
Change |
- 40 |
- 20 |
- 92 |
- 460 |
After |
10 p |
5 p |
2 p |
10 p |
3 u - 20 = 5 p --- (1)
2 u - 92 = 2 p --- (2)
Make p the same.
(1) x 2
6 u - 40 = 10 p --- (3)
(2) x 5
10 u - 460 = 10 p --- (4)
(4) = (3)
10 u - 460 = 6 u - 40
10 u - 6 u = 460 - 40
4 u = 420
1 u = 420 ÷ 4 = 105
Number of stickers that Adam has now
= 3 u - 20 + 2 u - 92
= 5 u - 112
= 5 x 105 - 112
= 525 - 112
= 413
Answer(s): 413