Final answer:
Sam was scheduled for a music lesson at 3:30 p.m. and was 15 minutes late, meaning he arrived at 3:45 p.m.
Step-by-step explanation:
The student's question is about calculating the time of arrival if someone is 15 minutes late to their appointment. If Sam's music lesson was scheduled for 3:30 p.m. and he was 15 minutes late, we would add 15 minutes to the original time. The calculation is straightforward:
3:30 p.m. + 15 minutes = 3:45 p.m.
Therefore, Sam arrived at his music lesson at 3:45 p.m.