The ratio of the number of green stickers to red stickers is 8 : 3.
After Adam buys another 50 red stickers and gives away 20 green stickers,
the ratio becomes of the number of green stickers to red stickers is 9 : 4.
How many stickers does Adam have now?
|
Make p the same (1) x 4 = (3) |
(1) Green |
(2) Red |
Make p the same (2) x 9 = (4) |
Before |
32 u |
8 u |
3 u |
27 u |
Change |
- 80 |
- 20 |
+ 50 |
+ 450 |
After |
36 p |
9 p |
4 p |
36 p |
8 u + 50 = 9 p --- (1)
3 u - 20 = 4 p --- (2)
Make p the same.
(1)
x 432 u - 80 = 36 p --- (3)
(2)
x 927 u + 450 = 36 p --- (4)
(3) = (4)
32 u - 80 = 27 u + 450
32 u - 27 u = 80 + 450
5 u = 530
1 u = 530 ÷ 5 = 106
Number of stickers that Adam have now
= 8 u + 50 + 3 u - 20
= 8 u + 3 u + 50 - 20
= 11 u + 30
= 11 x 106 + 30
= 1166 + 30
= 1196
Answer(s): 1196