Question

Ellen purchased a dishwasher, which cost $315 before the 9.22% sales tax. She used the machine an average of 10 times per week for the next six years, at which point she replaced it. Each time she ran the dishwasher it cost her $0.09 for water and $0.13 for electricity. What was the lifetime cost of Ellen's dishwasher?

Answer 1

the correct answer is A. $1030.44

Answer 2

Given:
Cost of dishwasher : 315 before sales tax
sales tax : 9.22%

Total cost = 315 * 1.0922 = 344.043

Average of 10 uses per week for the next 6 years before replacing it.
There are 52 weeks in a year.

10 uses per week * 52 weeks per year * 6 years = 3120 average uses

cost for water = 0.09 ; cost for electricity = 0.13 ; total cost per use = 0.22

0.22 * 3120 = 686.40 cost of use

purchase cost =    344.043
cost of use      =    686.40
lifetime cost     1,030.443