Elyse had a collection of 1880 red, silver and grey marbles. After Elyse gave away 270 red marbles, the number of red marbles was 200 fewer than the number of silver marbles. Given that the number of grey marbles was thrice as many as the number of silver marbles, how many red marbles did Elyse have at first?
| |
Red marbles |
Silver marbles |
Grey marbles |
Total |
| Before |
1 u + 270 |
1 u + 200 |
3 u + 600 |
1880 |
| Change |
- 270 |
|
|
|
| After |
1 u |
1 u + 200 |
3 u + 600 |
|
Number of grey marbles in the end
= 3 x (1 u + 200)
= 3 u + 600
Total number of marbles at first
= 1 u + 270 + 1 u + 200 + 3 u + 600
= 5 u + 1070
5 u + 1070 = 1880
5 u = 1880 - 1070
5 u = 810
1 u = 810 ÷ 5 = 162
Number of red marbles that Elyse had at first
= 1 u + 270
= 162 + 270
= 432
Answer(s): 432
