Question

Visa charges merchants roughly 10 cents plus a 1.5% transaction fee to use their cardsIf a store sets a minimum purchase of $10 before they accept Visa, and all you want to buy are some $0.50 candy bars (including tax), how many must you buy in order to use your Visa card instead of cash?

Answer 1

at least 20

Explanation:

You want to know how many $0.50 candy bars you must purchase so that your total purchase amount is a minimum of $10.

Setup

The value of your purchase is the product of the candy bar cost and the number purchased. If b represents the number of candy bars purchased, you want the total cost to be at least $10:

$0.50 × b ≥ $10.00

Solution

Dividing by the coefficient of 'b', we find ...

b ≥ 10/0.50

b ≥ 20

You must buy at least 20 candy bars in order to use your Visa card.