Question 1: The Living Ocean Institute would like to modernize their cafeteria to increase use
and raise funds for the Institute’s research projects. You designed a calming dining space in
aquatic blue and green tones. To keep costs down, the Institute has indicated that one cashier
should be enough. In their current cafeteria, they serve 120 meals a day during their operating
hours of 10 a.m. to 4 p.m. A cashier can ring up an order in 90 seconds. Do you think that one
cashier is enough? Why or why not? Can you foresee any problems that might result?
Answer 1: The cashier can process 40 customers per hour (90 seconds/60 seconds = x/1 so 90
seconds = 1.5 minutes, and 60 minutes in an hour/1.5 minutes per customer = x/1 hour so they
can process 40 customers per hour). They can process 240 customers over a six-hour day (40/1
= x/6, so x = 240). Since a cashier can handle 240 customers in a six-hour day and they are only
serving 120 meals per day, there would seem to be plenty of excess capacity. However, this
assumes that customers come at a constant rate throughout the day. So at peak periods
(probably 11:30 a.m. – 1:30 p.m. for lunch) the rate might be double the average hourly rate
and there could be significantly long waits for the cashier. Additionally, your striking design for
the new facility should bring in even bigger crowds, and unhappy paying guests who have a
long wait for the cashier might not come back to visit a second time.
Question 2: The Living Ocean Institute is an environmentally responsible organization, and your
design includes solar panels on the roof to supply all the building’s power requirements. The
sales representative from the solar panel company tells you that the total retail cost is $90,000,
but that the company offers a 10% discount as a sales promotion, plus a 5% discount for full
payment within 30 days. The sales representative claims the Living Ocean Institute will owe a
total of $76,500 with both discounts taken. Is the sales representative correct? Explain your
answer.
Answer 2: The sales representative is not correct. Some students will make the mistake of
adding 10% and 5% for a total discount of 15%. 15/100 = x/90,000 does equal a discount of
$13,500, and $90,000 - $13,500 does equal $76,500, but the cash discount should be applied
after the promotional discount is applied. So 10/100 = x/90,000 equals a promotional discount
of $9,000, leaving a net cost of $81,000 ($90,000 – $9,000). Applying the 5% discount to
$81,000 (5/100 = x/81,000) gives a discount of $4,050, so the net price of the panels is $76,950
($81,000 - $4,050).
Question 3: The Institute prides itself on the educational programs it offers local students in its
environmental classroom. It expects to staff the classroom with 2 scientists per field trip. To
maintain a good learning environment, the Institute wants no more than 36 students per field
trip and wants to schedule 4 field trips per day. Part of each field trip includes looking at a