The ratio of the number of red stickers to blue stickers is 3 : 1. After Ivan gives away 20 red stickers and buys another 80 blue stickers, there is equal number of red stickers and blue stickers. How many stickers does Ivan have now?
| |
Red |
Blue |
| Before |
3 u |
1 u |
| Change |
- 20 |
+ 80 |
| After |
3 u - 20 |
1 u + 80 |
The number of red stickers and blue stickers in the end is the same.
3 u - 20 = 1 u + 80
3 u - 1 u = 80 + 20
2 u = 100
1 u = 100 ÷ 2 = 50
Number of stickers that Ivan has now
= 3 u - 20 + 1 u + 80
= 3 u + 1 u - 20 + 80
= 4 u + 60
= 4 x 50 + 60
= 200 + 60
= 260
Answer(s): 260
