Final answer:
Jill works 8.25 hours a day, so any amount that is not 8.25 hours, such as 9 hours, is not part of her income function for a single weekday.
Step-by-step explanation:
The question is asking to determine the number of hours that are not part of the income function with respect to time for a single day, when Jill works from 7:15 A.M. to 3:30 P.M. To calculate this, we need to find out how many hours Jill works a day. Starting at 7:15 A.M. and finishing at 3:30 P.M. gives Jill an 8.25-hour workday (since 3:30 P.M. is 8 hours and 15 minutes after 7:15 A.M.). Therefore, option a) 8.25 hours represents her work hours and is part of her income function. Any number that is not 8.25 hours of work during the weekdays would not be part of her income function for that day. From the given choices, 9 hours (option d) is the correct answer as it is more than the hours Jill works, and hence would not be part of the income function.