Difference between revisions of "2008 AMC 8 Problems/Problem 3"

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==Solution 3==
 
==Solution 3==
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We can go back 2 weeks and say that Friday is the -1st of February. Going forward 2 days, we get that February 1st is Sunday. So our answer is <math>\boxed{\textbf{(A)}\ \text{Sunday}}</math>.
  
 
==See Also==
 
==See Also==
 
{{AMC8 box|year=2008|num-b=2|num-a=4}}
 
{{AMC8 box|year=2008|num-b=2|num-a=4}}
 
{{MAA Notice}}
 
{{MAA Notice}}

Latest revision as of 10:21, 24 August 2023

Problem

If February is a month that contains Friday the $13^{\text{th}}$, what day of the week is February 1?

$\textbf{(A)}\ \text{Sunday} \qquad \textbf{(B)}\ \text{Monday} \qquad \textbf{(C)}\ \text{Wednesday} \qquad \textbf{(D)}\ \text{Thursday}\qquad \textbf{(E)}\ \text{Saturday}$

Solution

We can go backwards by days, but we can also backwards by weeks. If we go backwards by weeks, we see that February 6 is a Friday. If we now go backwards by days, February 1 is a $\boxed{\textbf{(A)}\ \text{Sunday}}$

Solution 2

Since the days of the week repeat every 7 days and $1-13\equiv2\pmod7$, the day of the week of the day 2 days after February 13 is the same as the day of the week of February 1. Since we know that February 13 is a Friday, the day of the week of the day 2 days after February 13 is a Sunday so we get that February 1 is a $\boxed{\textbf{(A)}\ \text{Sunday}}$.

Solution 3

We can go back 2 weeks and say that Friday is the -1st of February. Going forward 2 days, we get that February 1st is Sunday. So our answer is $\boxed{\textbf{(A)}\ \text{Sunday}}$.

See Also

2008 AMC 8 (ProblemsAnswer KeyResources)
Preceded by
Problem 2
Followed by
Problem 4
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 AJHSME/AMC 8 Problems and Solutions

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