Min had the same number of silver, brown and black marbles at first. After giving some silver and brown marbles and 75 black marbles away, Min had 184 marbles left. There were 2 times as many silver marbles as brown marbles left. The number of black marbles left was 31 fewer than the number of silver marbles left. How many black marbles did she have at first?
| |
Brown |
Silver |
Black |
Total |
| Before |
2 u + 44 |
2 u + 44 |
2 u + 44 |
|
| Change |
- 1 u - 44 |
- 44 |
- 75 |
|
| After |
1 u |
2 u |
2 u - 31 |
184 |
Min had the same number of silver, brown and black marbles at first.
Total number of marbles in the end
= 1 u + 2 u + 2 u - 31
= 5 u - 31
5 u - 31 = 184
5 u = 184 + 31
5 u = 215
1 u = 215 ÷ 5 = 43
Number of black marbles that Min had at first
= 2 u - 31 + 75
= 2 u + 44
= 2 x 43 + 44
= 130
Answer(s): 130
