The ratio of the number of red stickers to green stickers is 4 : 3.
After Adam gives away 35 red stickers and gives away 42 green stickers,
the ratio becomes of the number of red stickers to green stickers is 5 : 2.
How many stickers does Adam have now?
|
Make p the same (1) x 2 = (3) |
(1) Red |
(2) Green |
Make p the same (2) x 5 = (4) |
Before |
8 u |
4 u |
3 u |
15 u |
Change |
- 70 |
- 35 |
- 42 |
- 210 |
After |
10 p |
5 p |
2 p |
10 p |
4 u - 35 = 5 p --- (1)
3 u - 42 = 2 p --- (2)
Make p the same.
(1) x 2
8 u - 70 = 10 p --- (3)
(2) x 5
15 u - 210 = 10 p --- (4)
(4) = (3)
15 u - 210 = 8 u - 70
15 u - 8 u = 210 - 70
7 u = 140
1 u = 140 ÷ 7 = 20
Number of stickers that Adam has now
= 4 u - 35 + 3 u - 42
= 7 u - 77
= 7 x 20 - 77
= 140 - 77
= 63
Answer(s): 63