The ratio of the number of green stickers to red stickers is 3 : 2.
After Adam gives away 98 green stickers and gives away 72 red stickers,
the ratio becomes of the number of green stickers to red stickers is 7 : 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 7 = (4) |
Before |
12 u |
3 u |
2 u |
14 u |
Change |
- 392 |
- 98 |
- 72 |
- 504 |
After |
28 p |
7 p |
4 p |
28 p |
3 u - 98 = 7 p --- (1)
2 u - 72 = 4 p --- (2)
Make p the same.
(1) x 4
12 u - 392 = 28 p --- (3)
(2) x 7
14 u - 504 = 28 p --- (4)
(4) = (3)
14 u - 504 = 12 u - 392
14 u - 12 u = 504 - 392
2 u = 112
1 u = 112 ÷ 2 = 56
Number of stickers that Adam has now
= 3 u - 98 + 2 u - 72
= 5 u - 170
= 5 x 56 - 170
= 280 - 170
= 110
Answer(s): 110