To calculate your bank balance at the end of July after accounting for the details you've provided, we follow these steps:
1. **Starting Balance (End of July)**: $50,000
2. **Check for Contractor**: Margo has not cashed her check for $2,000, so this amount is still considered part of your balance.
3. **Deposit Made on July 31**: You made a deposit of $500. However, since your bank adds deposits the day after you deposit them, this deposit will


