PJ will begin her cake deliveries at 12:20. She asked to remind her 30 minutes before she has to leave. What time should I remind PJ about her deliveries?

At 11:50

Step-by-step explanation:

1. Subtract the hours and the minutes separately

12: 20

- 0: 30

12: - 10

2. If the minutes are negative, subtract 1 from the hours and add 60 to the minutes.

12: - 10

- 1: + 60

11: 50

You should remind PJ about her deliveries at 11:50.