The ratio of the number of green stickers to red stickers is 4 : 3.
After Adam gives away 80 green stickers and gives away 78 red stickers,
the ratio becomes of the number of green stickers to red stickers is 8 : 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 8 = (4) |
Before |
12 u |
4 u |
3 u |
24 u |
Change |
- 240 |
- 80 |
- 78 |
- 624 |
After |
24 p |
8 p |
3 p |
24 p |
4 u - 80 = 8 p --- (1)
3 u - 78 = 3 p --- (2)
Make p the same.
(1) x 3
12 u - 240 = 24 p --- (3)
(2) x 8
24 u - 624 = 24 p --- (4)
(4) = (3)
24 u - 624 = 12 u - 240
24 u - 12 u = 624 - 240
12 u = 384
1 u = 384 ÷ 12 = 32
Number of stickers that Adam has now
= 4 u - 80 + 3 u - 78
= 7 u - 158
= 7 x 32 - 158
= 224 - 158
= 66
Answer(s): 66