Elapsed time worksheet for practicing time calculations to the quarter hour.

To solve the problem of finding the elapsed time between the given start and end times, we need to calculate the difference in hours and minutes for each pair. Let's go through each one step by step.

1. 2:45 P.M. to 5:15 P.M.

- Start: 2:45 P.M.
- End: 5:15 P.M.
- Difference:
- From 2:45 P.M. to 3:00 P.M.: 15 minutes
- From 3:00 P.M. to 5:00 P.M.: 2 hours
- From 5:00 P.M. to 5:15 P.M.: 15 minutes
- Total: 2 hours and 30 minutes

Answer: 2 hours 30 minutes

2. 6:30 P.M. to 8:45 P.M.

- Start: 6:30 P.M.
- End: 8:45 P.M.
- Difference:
- From 6:30 P.M. to 7:00 P.M.: 30 minutes
- From 7:00 P.M. to 8:00 P.M.: 1 hour
- From 8:00 P.M. to 8:45 P.M.: 45 minutes
- Total: 2 hours 15 minutes

Answer: 2 hours 15 minutes

3. 12:00 P.M. to 9:15 P.M.

- Start: 12:00 P.M.
- End: 9:15 P.M.
- Difference:
- From 12:00 P.M. to 9:00 P.M.: 9 hours
- From 9:00 P.M. to 9:15 P.M.: 15 minutes
- Total: 9 hours 15 minutes

Answer: 9 hours 15 minutes

4. 8:15 P.M. to 11:30 P.M.

- Start: 8:15 P.M.
- End: 11:30 P.M.
- Difference:
- From 8:15 P.M. to 9:00 P.M.: 45 minutes
- From 9:00 P.M. to 11:00 P.M.: 2 hours
- From 11:00 P.M. to 11:30 P.M.: 30 minutes
- Total: 3 hours 15 minutes

Answer: 3 hours 15 minutes

5. 10:45 P.M. to 12:15 A.M.

- Start: 10:45 P.M.
- End: 12:15 A.M.
- Difference:
- From 10:45 P.M. to 11:00 P.M.: 15 minutes
- From 11:00 P.M. to 12:00 A.M.: 1 hour
- From 12:00 A.M. to 12:15 A.M.: 15 minutes
- Total: 1 hour 30 minutes

Answer: 1 hour 30 minutes

6. 8:30 A.M. to 3:15 P.M.

- Start: 8:30 A.M.
- End: 3:15 P.M.
- Difference:
- From 8:30 A.M. to 9:00 A.M.: 30 minutes
- From 9:00 A.M. to 3:00 P.M.: 6 hours
- From 3:00 P.M. to 3:15 P.M.: 15 minutes
- Total: 6 hours 45 minutes

Answer: 6 hours 45 minutes

7. 9:00 A.M. to 11:45 A.M.

- Start: 9:00 A.M.
- End: 11:45 A.M.
- Difference:
- From 9:00 A.M. to 11:00 A.M.: 2 hours
- From 11:00 A.M. to 11:45 A.M.: 45 minutes
- Total: 2 hours 45 minutes

Answer: 2 hours 45 minutes

8. 4:45 A.M. to 10:30 A.M.

- Start: 4:45 A.M.
- End: 10:30 A.M.
- Difference:
- From 4:45 A.M. to 5:00 A.M.: 15 minutes
- From 5:00 A.M. to 10:00 A.M.: 5 hours
- From 10:00 A.M. to 10:30 A.M.: 30 minutes
- Total: 5 hours 45 minutes

Answer: 5 hours 45 minutes

9. 6:30 A.M. to 9:15 A.M.

- Start: 6:30 A.M.
- End: 9:15 A.M.
- Difference:
- From 6:30 A.M. to 7:00 A.M.: 30 minutes
- From 7:00 A.M. to 9:00 A.M.: 2 hours
- From 9:00 A.M. to 9:15 A.M.: 15 minutes
- Total: 2 hours 45 minutes

Answer: 2 hours 45 minutes

10. 11:00 A.M. to 11:45 A.M.

- Start: 11:00 A.M.
- End: 11:45 A.M.
- Difference:
- From 11:00 A.M. to 11:45 A.M.: 45 minutes
- Total: 0 hours 45 minutes

Answer: 0 hours 45 minutes

11. 3:00 P.M. to 9:45 P.M.

- Start: 3:00 P.M.
- End: 9:45 P.M.
- Difference:
- From 3:00 P.M. to 9:00 P.M.: 6 hours
- From 9:00 P.M. to 9:45 P.M.: 45 minutes
- Total: 6 hours 45 minutes

Answer: 6 hours 45 minutes

Final Answers:

1. 2 hours 30 minutes
2. 2 hours 15 minutes
3. 9 hours 15 minutes
4. 3 hours 15 minutes
5. 1 hour 30 minutes
6. 6 hours 45 minutes
7. 2 hours 45 minutes
8. 5 hours 45 minutes
9. 2 hours 45 minutes
10. 0 hours 45 minutes
11. 6 hours 45 minutes

Boxed Final Answer:
\[
\boxed{
\begin{array}{ll}
1. & 2 \text{ hours } 30 \text{ minutes} \\
2. & 2 \text{ hours } 15 \text{ minutes} \\
3. & 9 \text{ hours } 15 \text{ minutes} \\
4. & 3 \text{ hours } 15 \text{ minutes} \\
5. & 1 \text{ hour } 30 \text{ minutes} \\
6. & 6 \text{ hours } 45 \text{ minutes} \\
7. & 2 \text{ hours } 45 \text{ minutes} \\
8. & 5 \text{ hours } 45 \text{ minutes} \\
9. & 2 \text{ hours } 45 \text{ minutes} \\
10. & 0 \text{ hours } 45 \text{ minutes} \\
11. & 6 \text{ hours } 45 \text{ minutes} \\
\end{array}
}
\]