The cho family is buying a new refrigerator. They choose a 20-cubic foot refrigerator with a regular price of $678. The sales tax rate in their town is 8.5%. A mail-in rebate of $120 was given after sales tax was computed, what is the final cost of the refrigerator?

$615.63

Step-by-step explanation:

In this question, we are asked to calculate the cost of a refrigerator given the original cost, tax amount and rebate. We proceed as follows:

Firstly, we calculate the tax to be paid. This is at 8.5%.

Mathematically, tax amount = 8.5/100 * 678 = $57.63

Total amount to be paid is thus 57.63+678 = $735.63

We subtract the amount for the rebate = 735.63 - 120 = $615.63

details

step-by-step explanation:

(a) {a₁, a₁r, a₁r², … a₁rⁿ⁻¹, …}

(b) $59 398

step-by-step explanation:

(a) the annual sequence of profits

aₙ = a₁rⁿ⁻¹

the model for the sequence of profits is {a₁, a₁r, a₁r², … a₁rⁿ⁻¹, …} .

(b) profit after 15 yr

  a₁ = $ 30 000

  r = 1.05

a₁₅ = 30 000 × 1.05¹⁴

a₁₅ = 30 000 × 1.979 93

a₁₅ = $59 398

the profit in year 15 will be $59 398.