The ratio of the number of green stickers to red stickers is 5 : 2.
After Adam buys another 34 red stickers and gives away 20 green stickers,
the ratio becomes of the number of green stickers to red stickers is 5 : 3.
How many stickers does Adam have now?
|
Make p the same (1) x 3 = (3) |
(1) Green |
(2) Red |
Make p the same (2) x 5 = (4) |
Before |
15 u |
5 u |
2 u |
10 u |
Change |
- 60 |
- 20 |
+ 34 |
+ 170 |
After |
15 p |
5 p |
3 p |
15 p |
5 u + 34 = 5 p --- (1)
2 u - 20 = 3 p --- (2)
Make p the same.
(1)
x 315 u - 60 = 15 p --- (3)
(2)
x 510 u + 170 = 15 p --- (4)
(3) = (4)
15 u - 60 = 10 u + 170
15 u - 10 u = 60 + 170
5 u = 230
1 u = 230 ÷ 5 = 46
Number of stickers that Adam have now
= 5 u + 34 + 2 u - 20
= 5 u + 2 u + 34 - 20
= 7 u + 14
= 7 x 46 + 14
= 322 + 14
= 336
Answer(s): 336