The ratio of the number of green stickers to red stickers is 5 : 2.
After Adam gives away 58 green stickers and gives away 84 red stickers,
the ratio becomes of the number of green stickers to red stickers is 7 : 2.
How many stickers does Adam have now?
|
Make p the same (1) x 2 = (3) |
(1) Green |
(2) Red |
Make p the same (2) x 7 = (4) |
Before |
10 u |
5 u |
2 u |
14 u |
Change |
- 116 |
- 58 |
- 84 |
- 588 |
After |
14 p |
7 p |
2 p |
14 p |
5 u - 58 = 7 p --- (1)
2 u - 84 = 2 p --- (2)
Make p the same.
(1) x 2
10 u - 116 = 14 p --- (3)
(2) x 7
14 u - 588 = 14 p --- (4)
(4) = (3)
14 u - 588 = 10 u - 116
14 u - 10 u = 588 - 116
4 u = 472
1 u = 472 ÷ 4 = 118
Number of stickers that Adam has now
= 5 u - 58 + 2 u - 84
= 7 u - 142
= 7 x 118 - 142
= 826 - 142
= 684
Answer(s): 684