Final answer:
The gross income for the month, given the cash income of $200 and check income of $300, would be $500.
Step-by-step explanation:
The formula to calculate the gross income for the month is to add together all the incomes. Given that the cash income is $200 and the check income is $300, we need to find the credit card charges. Therefore, the gross income for the month would equal $200 (cash) + $300 (checks) = $500.