Question

The Reed and the Merrill families are comparing their utility costs for the past month. The following is a list of the appliances that the families are using to make their comparisons:

Reed Family Appliances
Merrill Family Appliances
Gas range
5 cents per day
Electric range
13 cents per day
Gas dryer - 1 load per day
10 cents per load
Gas dryer - 1 load per day
10 cents per load
Electric water heater
90 cents per day
Gas water heater
40 cents per day
Typical later model refrigerator
16 cents per day
Energy Star-labeled refrigerator
12 cents per day

Assuming that the families use the same appliances in the same way, who spends more to run these appliances in a given 30 day period and by how much?
a.
The Reed family spends $13.80 more than the Merrill family.
b.
The Reed family spends $0.46 more than the Merrill family.
c.
The Merrill family spends $58.80 more than the Reed family.
d.
The Merrill family spends $18.60 more than the Reed family.

Answer 1

Reed daily: 5 + 10 + 90 + 16 = 121 cents = $1.21/day.
Merrill daily: 13 + 10 + 40 + 12 = 75 cents = $0.75/day.
Difference per day = $1.21 − $0.75 = $0.46 → over 30 days = $0.46 × 30 = $13.80.

Answer: a. The Reed family spends $13.80 more than the Merrill family.