Skip to main content

2011 AMC 10A Problem 1

Problem 1 of 25EasierArithmetic

A cell phone plan costs $20\$20 each month, plus 55¢ per text message sent, plus 1010¢ for each minute used over 3030 hours. In January Michelle sent 100100 text messages and talked for 30.530.5 hours. How much did she have to pay?

Answer choices

Show solution

Solution

Michelle has to pay $20\$20 for the monthly fee. Her text messages cost 100⋅5=500100\cdot 5=500 cents, or $5.\$5. Finally she talked for 0.50.5 hours, 3030 minutes, over 3030 hours. This means her extra charge is 30⋅10=30030\cdot10=300 cents, or $3.\$3. Her total cost is $20+$5+$3=$28. \$20 + \$5 + \$3 = \$28. Thus, D is the correct answer.
AoPS wiki

Tagged: money · unit conversion

More practice