Cindy had a collection of 2050 red, silver and blue marbles. After Cindy gave away 310 red marbles, the number of red marbles was 240 fewer than the number of silver marbles. Given that the number of blue marbles was four times as many as the number of silver marbles, how many red marbles did Cindy have at first?
| |
Red marbles |
Silver marbles |
Blue marbles |
Total |
| Before |
1 u + 310 |
1 u + 240 |
4 u + 960 |
2050 |
| Change |
- 310 |
|
|
|
| After |
1 u |
1 u + 240 |
4 u + 960 |
|
Number of blue marbles in the end
= 4 x (1 u + 240)
= 4 u + 960
Total number of marbles at first
= 1 u + 310 + 1 u + 240 + 4 u + 960
= 6 u + 1510
6 u + 1510 = 2050
6 u = 2050 - 1510
6 u = 540
1 u = 540 ÷ 6 = 90
Number of red marbles that Cindy had at first
= 1 u + 310
= 90 + 310
= 400
Answer(s): 400
