The ratio of the number of green stickers to blue stickers is 7 : 2. After Dylan gives away 20 green stickers and buys another 70 blue stickers, there is equal number of green stickers and blue stickers. How many stickers does Dylan have now?
| |
Green |
Blue |
| Before |
7 u |
2 u |
| Change |
- 20 |
+ 70 |
| After |
7 u - 20 |
2 u + 70 |
The number of green stickers and blue stickers in the end is the same.
7 u - 20 = 2 u + 70
7 u - 2 u = 70 + 20
5 u = 90
1 u = 90 ÷ 5 = 18
Number of stickers that Dylan has now
= 7 u - 20 + 2 u + 70
= 7 u + 2 u - 20 + 70
= 9 u + 50
= 9 x 18 + 50
= 162 + 50
= 212
Answer(s): 212
