Final answer:
In accrual basis accounting, the net income for May is $250 based on the given information.
Step-by-step explanation:
In accrual basis accounting, revenues are recognized when they are earned, regardless of when they are received, and expenses are recognized when they are incurred, regardless of when they are paid. Based on the given information, the revenue for May is $400 from cash payments and $100 on account, totaling $500. The expenses for May are $100 for April's piano rental bill and $150 for May's piano rental bill. Therefore, the net income for May is calculated as follows:
Net Income = Revenues - Expenses
Net Income = $500 - ($100 + $150) = $250.