Question

1. "Grace purchased a dishwasher, which cost $550 before the 7.85% 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 $0.12 for water and $0.15 for
electricity. What was the lifetime cost of Grace's dishwasher?


a $1,030.44
b. $593.18
C. $842.4
d. $1435.58

Answer 1

First, let's calculate the sales tax on the dishwasher:

Sales tax = 7.85% of $550 = 0.0785 * $550 = $43.18

So the total cost of the dishwasher with sales tax is:

$550 + $43.18 = $593.18

Next, let's calculate the cost of running the dishwasher each week:

Water cost = $0.12 per use * 10 uses per week = $1.20 per week

Electricity cost = $0.15 per use * 10 uses per week = $1.50 per week

Total cost per week = $1.20 + $1.50 = $2.70 per week

Since Grace used the dishwasher for 6 years, or 52 weeks per year * 6 years = 312 weeks, the total cost of running the dishwasher is:

Total cost = $2.70 per week * 312 weeks = $842.40

Therefore, the lifetime cost of Grace's dishwasher, including the initial purchase price and the cost of running it, is:

$593.18 + $842.40 = $1,435.58

So the correct answer is (d) $1,435.58.