Linda had a collection of 2450 blue, green and grey balls. After Linda gave away 220 blue balls, the number of blue balls was 170 fewer than the number of green balls. Given that the number of grey balls was thrice as many as the number of green balls, how many blue balls did Linda have at first?
| |
Blue balls |
Green balls |
Grey balls |
Total |
| Before |
1 u + 220 |
1 u + 170 |
3 u + 510 |
2450 |
| Change |
- 220 |
|
|
|
| After |
1 u |
1 u + 170 |
3 u + 510 |
|
Number of grey balls in the end
= 3 x (1 u + 170)
= 3 u + 510
Total number of balls at first
= 1 u + 220 + 1 u + 170 + 3 u + 510
= 5 u + 900
5 u + 900 = 2450
5 u = 2450 - 900
5 u = 1550
1 u = 1550 ÷ 5 = 310
Number of blue balls that Linda had at first
= 1 u + 220
= 310 + 220
= 530
Answer(s): 530
