Difference between revisions of "2014 AMC 10A Problems/Problem 10"

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==Solution==
 
==Solution==
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Let <math>a=1</math>. Our list is <math>\{1,2,3,4,5\}</math> with an average of <math>15\div 5=3</math>. Our next set starting with <math>3</math> is <math>\{3,4,5,6,7\}</math>. Our average is <math>25\div 5=5</math>.
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Therefore, we notice that <math>5=1+4</math> which means that the answer is <math>\boxed{\textbf{(B)}\ a+4}</math>.
  
 
==See Also==
 
==See Also==

Revision as of 22:28, 6 February 2014

Problem

Five positive consecutive integers starting with $a$ have average $b$. What is the average of $5$ consecutive integers that start with $b$?

$\textbf{(A)}\ a+3\qquad\textbf{(B)}\ a+4\qquad\textbf{(C)}\ a+5\qquad\textbf{(D)}}\ a+6\qquad\textbf{(E)}\ a+7$ (Error compiling LaTeX. Unknown error_msg)

Solution

Let $a=1$. Our list is $\{1,2,3,4,5\}$ with an average of $15\div 5=3$. Our next set starting with $3$ is $\{3,4,5,6,7\}$. Our average is $25\div 5=5$.

Therefore, we notice that $5=1+4$ which means that the answer is $\boxed{\textbf{(B)}\ a+4}$.

See Also

2014 AMC 10A (ProblemsAnswer KeyResources)
Preceded by
Problem 9
Followed by
Problem 11
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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