Question

A cell phone plan costs $\$20$ each month, plus $5$ ¢ per text message sent, plus $10$ ¢ for each minute used over $30$ hours. In January Michelle sent $100$ text messages and talked for $30.5$ hours. How much did she have to pay?

$\$24.00$

$\$24.50$

$\$25.50$

$\$28.00$

$\$30.00$

Answer: D

Concepts:money unit conversion

Difficulty rating: 720

Small Hint:

Convert the texting charge and excess-call charge into dollars

Big Hint:

Only the extra half hour is billed by the minute

Solution:

Michelle has to pay $\$20$ for the monthly fee. Her text messages cost $100\cdot 5=500$ cents, or $\$5.$ Finally she talked for $0.5$ hours, $30$ minutes, over $30$ hours.

This means her extra charge is $30\cdot10=300$ cents, or $\$3.$

Her total cost is $\$20 + \$5 + \$3 = \$28.$

Thus, D is the correct answer.

2011 AMC 10A Problem 1

Answer: D

Difficulty rating: 720

Small Hint:

Big Hint:

Solution:

Problem 1 in Other Years