The ratio of the number of red stamps to blue stamps is 3 : 1. After Jeremy gives away 60 red stamps and buys another 80 blue stamps, there is equal number of red stamps and blue stamps. How many stamps does Jeremy have now?
| |
Red |
Blue |
| Before |
3 u |
1 u |
| Change |
- 60 |
+ 80 |
| After |
3 u - 60 |
1 u + 80 |
The number of red stamps and blue stamps in the end is the same.
3 u - 60 = 1 u + 80
3 u - 1 u = 80 + 60
2 u = 140
1 u = 140 ÷ 2 = 70
Number of stamps that Jeremy has now
= 3 u - 60 + 1 u + 80
= 3 u + 1 u - 60 + 80
= 4 u + 20
= 4 x 70 + 20
= 280 + 20
= 300
Answer(s): 300
