Final answer:
The arrival time in Los Angeles is 10 am on Saturday.
Step-by-step explanation:
The time difference between Boston (75 W) and Los Angeles (120 W) is 45 degrees of longitude. Since one hour corresponds to 15 degrees of longitude, the time difference between Boston and Los Angeles is 3 hours.
Given that the flight takes 5 hours, you need to add the flight duration to the departure time. Therefore, the arrival time in Los Angeles would be 10 am on Saturday.