Difference between revisions of "2016 AMC 10B Problems/Problem 4"

(Video Solution)
 
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Since <math>119</math> is divisible by <math>7</math>, both must have been the same day of the week, so the answer is <math>\textbf{(B)}\ \text{Monday}</math>.
 
Since <math>119</math> is divisible by <math>7</math>, both must have been the same day of the week, so the answer is <math>\textbf{(B)}\ \text{Monday}</math>.
  
 
+
==Video Solution==
 +
https://youtu.be/8_xEaEIJZ24
  
 
~savannahsolver
 
~savannahsolver
UR MOM
 
  
 
==See Also==
 
==See Also==
 
{{AMC10 box|year=2016|ab=B|num-b=3|num-a=5}}
 
{{AMC10 box|year=2016|ab=B|num-b=3|num-a=5}}
 
{{MAA Notice}}
 
{{MAA Notice}}

Latest revision as of 15:34, 30 April 2021

Problem

Zoey read $15$ books, one at a time. The first book took her $1$ day to read, the second book took her $2$ days to read, the third book took her $3$ days to read, and so on, with each book taking her $1$ more day to read than the previous book. Zoey finished the first book on a Monday, and the second on a Wednesday. On what day the week did she finish her $15$th book?

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

Solution

The process took $1+2+3+\ldots+13+14+15=120$ days, so the last day was $119$ days after the first day. Since $119$ is divisible by $7$, both must have been the same day of the week, so the answer is $\textbf{(B)}\ \text{Monday}$.

Video Solution

https://youtu.be/8_xEaEIJZ24

~savannahsolver

See Also

2016 AMC 10B (ProblemsAnswer KeyResources)
Preceded by
Problem 3
Followed by
Problem 5
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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