Answer:
The answer is 8:50 PM.
Explanation:
If it's 7:20 PM, then what time is it 90 minutes from now?
Start with 30. It would be 7:50 PM. So, add 10 more minutes (with 50 minutes more to add) and you have 8:00 PM. Add your last 50 minutes. The time would be, as shown above, 8:50 PM.