Cathy and Min had an equal number of marbles at first. After Cathy gave 13 marbles to Min, Min had 30 marbles. How many marbles does Cathy have in the end?
| |
Cathy |
Min |
| Before |
1 u |
1 u |
| Change |
- 13 |
+ 13 |
| After |
1 u - 13 |
30 |
Number of marbles that Min had at first
= 30 - 13
= 17
1 u = 17
Number of marbles that Cathy had at first = 17
Number of marbles that Cathy had in the end
= 1 u - 13
= 17 - 13
= 4
Answer(s): 4
