Emma had a collection of 1700 brown, grey and silver balls. After Emma gave away 230 brown balls, the number of brown balls was 210 fewer than the number of grey balls. Given that the number of silver balls was twice as many as the number of grey balls, how many brown balls did Emma have at first?
| |
Brown balls |
Grey balls |
Silver balls |
Total |
| Before |
1 u + 230 |
1 u + 210 |
2 u + 420 |
1700 |
| Change |
- 230 |
|
|
|
| After |
1 u |
1 u + 210 |
2 u + 420 |
|
Number of silver balls in the end
= 2 x (1 u + 210)
= 2 u + 420
Total number of balls at first
= 1 u + 230 + 1 u + 210 + 2 u + 420
= 4 u + 860
4 u + 860 = 1700
4 u = 1700 - 860
4 u = 840
1 u = 840 ÷ 4 = 210
Number of brown balls that Emma had at first
= 1 u + 230
= 210 + 230
= 440
Answer(s): 440
