When Riley left her house in the morning, her cell phone battery was partially charged. The charge remaining in Riley's battery, as a percentage, can be modeled by
the equation B = 40 – 5t, where t is the number of hours since Riley left her
house. What is the x-intercept of the equation and what is its interpretation in the
context of the problem?

The x-intercept of the function is ___ which represents
A. the charge of the battery when Riley left her hours
B. The charge of the battery when Riley woke up
C. The percentage charge that Riley’s phone loses loses each hour
D. The number of hours until Riley’s phone dies

Acaterer knows he will need 60, 50, 80, 40 and 50 dinner napkins on five successive evenings. he can purchase new napkins initially at 25 cents each, after which he can have dirty napkins laundered by a fast one-day laundry service (i.e., dirty napkins given at the end of the day will be ready for use the following day) at 15 cents each, or by a slow two-day service at 8 cents each or both. the caterer wants to know how many napkins he should purchase initially and how many dirty napkins should be laundered by fast and slow service on each of the days in order to minimize his total costs. formulate the caterer’s problem as a linear program as follows (you must state any assumptions you make): a. define all variables clearly. how many are there? b. write out the constraints that must be satisfied, briefly explaining each. (do not simplify.) write out the objective function to be minimized. (do not simplify.)