You want to buy an item that costs $100. which of these is the most cost-effective choice for buying the item? . a. using a paid membership card to buy it at a 10 percent discount. b. buying it online at a 10 percent discount with a $5 shipping charge. c. buying it at a 10 percent discount without sales tax.

Answer

c. buying it at a 10 percent discount without sales tax.

Explanation

We are going to compare the 3 choices and then determine the most cost effective.

a. using a paid membership card to buy it at a 10 percent discount.

10% of $100 = 10/100×100 = $10

cost = $100 - $10 = $90

On top of this $90 there is the charges of the membership card.

b. buying it online at a 10 percent discount with a $5 shipping charge.

100%-10% = 90%

90% of 100 = $90

Cost: $90 + $5 = $95

c. buying it at a 10 percent discount without sales tax.

100% - 10% = 90%

90/100 × 100 = $90. This is the must cost effective method since there is no other cost involved.