Cathy had the same number of red, black and blue coins at first. After giving some red and black coins and 70 blue coins away, Cathy had 215 coins left. There were 4 times as many red coins as black coins left. The number of blue coins left was 46 fewer than the number of red coins left. How many blue coins did she have at first?
| |
Black |
Red |
Blue |
Total |
| Before |
4 u + 24 |
4 u + 24 |
4 u + 24 |
|
| Change |
- 3 u - 24 |
- 24 |
- 70 |
|
| After |
1 u |
4 u |
4 u - 46 |
215 |
Cathy had the same number of red, black and blue coins at first.
Total number of coins in the end
= 1 u + 4 u + 4 u - 46
= 9 u - 46
9 u - 46 = 215
9 u = 215 + 46
9 u = 261
1 u = 261 ÷ 9 = 29
Number of blue coins that Cathy had at first
= 4 u - 46 + 70
= 4 u + 24
= 4 x 29 + 24
= 140
Answer(s): 140
