The ratio of the number of red stickers to green stickers is 3 : 1.
After Adam buys another 31 green stickers and gives away 11 red stickers,
the ratio becomes of the number of red stickers to green stickers is 5 : 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 5 = (4) |
Before |
9 u |
3 u |
1 u |
5 u |
Change |
- 33 |
- 11 |
+ 31 |
+ 155 |
After |
15 p |
5 p |
3 p |
15 p |
3 u + 31 = 5 p --- (1)
1 u - 11 = 3 p --- (2)
Make p the same.
(1)
x 39 u - 33 = 15 p --- (3)
(2)
x 55 u + 155 = 15 p --- (4)
(3) = (4)
9 u - 33 = 5 u + 155
9 u - 5 u = 33 + 155
4 u = 188
1 u = 188 ÷ 4 = 47
Number of stickers that Adam have now
= 3 u + 31 + 1 u - 11
= 3 u + 1 u + 31 - 11
= 4 u + 20
= 4 x 47 + 20
= 188 + 20
= 208
Answer(s): 208