The ratio of the number of red stickers to green stickers is 3 : 1.
After Adam buys another 50 green stickers and gives away 15 red stickers,
the ratio becomes of the number of red stickers to green stickers is 4 : 3.
How many stickers does Adam have now?
|
Make p the same (1) x 3 = (3) |
(1) Red |
(2) Green |
Make p the same (2) x 4 = (4) |
Before |
9 u |
3 u |
1 u |
4 u |
Change |
- 45 |
- 15 |
+ 50 |
+ 200 |
After |
12 p |
4 p |
3 p |
12 p |
3 u + 50 = 4 p --- (1)
1 u - 15 = 3 p --- (2)
Make p the same.
(1)
x 39 u - 45 = 12 p --- (3)
(2)
x 44 u + 200 = 12 p --- (4)
(3) = (4)
9 u - 45 = 4 u + 200
9 u - 4 u = 45 + 200
5 u = 245
1 u = 245 ÷ 5 = 49
Number of stickers that Adam have now
= 3 u + 50 + 1 u - 15
= 3 u + 1 u + 50 - 15
= 4 u + 35
= 4 x 49 + 35
= 196 + 35
= 231
Answer(s): 231