Answer:
The history class started at 2:35 pm
Explanation:
To find the before time or starting time, we need to subtract 55 min from 3:30.
We cannot subtract 55 min from 30 min.
1 hour = 60 minutes. 3 : 30 can be written as 2: 90 minutes
Now subtract,
2 : 90
- : 55
2 : 35
The history class started at 2:35 pm