Difference between revisions of "2011 AMC 12A Problems/Problem 1"

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== Problem ==
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A cell phone plan costs <math>20</math> dollars each month, plus <math>5</math> cents per text message sent, plus <math>10</math> cents for each minute used over <math>30</math> hours. In January Michelle sent <math>100</math> text messages and talked for <math>30.5</math> hours. How much did she have to pay?
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<math>
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\textbf{(A)}\ 24.00 \qquad
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\textbf{(B)}\ 24.50 \qquad
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\textbf{(C)}\ 25.50 \qquad
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\textbf{(D)}\ 28.00 \qquad
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\textbf{(E)}\ 30.00 </math>
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== Solution ==
 
== Solution ==
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The base price of Michelle's cell phone plan is <math>20</math> dollars.
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If she sent <math>100</math> text messages and it costs <math>5</math> cents per text, then she must have spent <math>500</math> cents for texting, or <math>5</math> dollars. She talked for <math>30.5</math> hours, but <math>30.5-30</math> will give us the amount of time exceeded past 30 hours.
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<math>30.5-30=.5</math> hours <math>=30</math> minutes.
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Since the price for phone calls is <math>10</math> cents per minute, the additional amount Michelle has to pay for phone calls is <math>30*10=300</math> cents, or <math>3</math> dollars.
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Adding <math>20+5+3</math> dollars <math>\boxed{\$28 \textbf{ (D)}}</math>.
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==Video Solution==
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https://youtu.be/tWz5T2Db9AY
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~savannahsolver
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== See also ==
 
== See also ==
 
{{AMC12 box|year=2011|before=First Problem|num-a=2|ab=A}}
 
{{AMC12 box|year=2011|before=First Problem|num-a=2|ab=A}}
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{{AMC10 box|year=2011|before=First Problem|num-a=2|ab=A}}
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{{MAA Notice}}

Latest revision as of 11:09, 19 October 2023

Problem

A cell phone plan costs $20$ dollars each month, plus $5$ cents per text message sent, plus $10$ cents 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?

$\textbf{(A)}\ 24.00 \qquad \textbf{(B)}\ 24.50 \qquad \textbf{(C)}\ 25.50 \qquad \textbf{(D)}\ 28.00 \qquad \textbf{(E)}\ 30.00$


Solution

The base price of Michelle's cell phone plan is $20$ dollars. If she sent $100$ text messages and it costs $5$ cents per text, then she must have spent $500$ cents for texting, or $5$ dollars. She talked for $30.5$ hours, but $30.5-30$ will give us the amount of time exceeded past 30 hours. $30.5-30=.5$ hours $=30$ minutes. Since the price for phone calls is $10$ cents per minute, the additional amount Michelle has to pay for phone calls is $30*10=300$ cents, or $3$ dollars. Adding $20+5+3$ dollars $\boxed{$28 \textbf{ (D)}}$.

Video Solution

https://youtu.be/tWz5T2Db9AY

~savannahsolver

See also

2011 AMC 12A (ProblemsAnswer KeyResources)
Preceded by
First Problem
Followed by
Problem 2
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
All AMC 12 Problems and Solutions
2011 AMC 10A (ProblemsAnswer KeyResources)
Preceded by
First Problem
Followed by
Problem 2
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
All AMC 10 Problems and Solutions

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