Dana had a collection of 2310 blue, yellow and red balls. After Dana gave away 260 blue balls, the number of blue balls was 100 fewer than the number of yellow balls. Given that the number of red balls was thrice as many as the number of yellow balls, how many blue balls did Dana have at first?
| |
Blue balls |
Yellow balls |
Red balls |
Total |
| Before |
1 u + 260 |
1 u + 100 |
3 u + 300 |
2310 |
| Change |
- 260 |
|
|
|
| After |
1 u |
1 u + 100 |
3 u + 300 |
|
Number of red balls in the end
= 3 x (1 u + 100)
= 3 u + 300
Total number of balls at first
= 1 u + 260 + 1 u + 100 + 3 u + 300
= 5 u + 660
5 u + 660 = 2310
5 u = 2310 - 660
5 u = 1650
1 u = 1650 ÷ 5 = 330
Number of blue balls that Dana had at first
= 1 u + 260
= 330 + 260
= 590
Answer(s): 590
