Art of Problem Solving
AoPS Online
Math texts, online classes, and more
for students in grades 5-12.
Visit AoPS Online ‚
Books for Grades 5-12 Online Courses
Beast Academy
Engaging math books and online learning
for students ages 6-13.
Visit Beast Academy ‚
Books for Ages 6-13 Beast Academy Online
AoPS Academy
Small live classes for advanced math
and language arts learners in grades 2-12.
Visit AoPS Academy ‚
Find a Physical Campus Visit the Virtual Campus

Difference between revisions of "2016 AMC 8 Problems/Problem 3"

m
Line 5: Line 5:
 
==Solution==
 
==Solution==
 
{{solution}}
 
{{solution}}
 +
 +
 +
Solution (Dhman2727):
 +
 +
We see that <math>80-70=10</math> and <math>90-70=20</math>.  We then find that <math>10+20=30</math>.  We want our average to be <math>70</math>, so we find <math>70-30=40</math>.  So our final answer is <math>\textbf{(A) }40</math>.

Revision as of 09:42, 23 November 2016

3. Four students take an exam. Three of their scores are $70, 80,$ and $90$. If the average of their four scores is $70$, then what is the remaining score?

$\textbf{(A) }40\qquad\textbf{(B) }50\qquad\textbf{(C) }55\qquad\textbf{(D) }60\qquad \textbf{(E) }70$

Solution

This problem needs a solution. If you have a solution for it, please help us out by adding it.


Solution (Dhman2727):

We see that $80-70=10$ and $90-70=20$. We then find that $10+20=30$. We want our average to be $70$, so we find $70-30=40$. So our final answer is $\textbf{(A) }40$.

Retrieved from "https://artofproblemsolving.com/wiki/index.php?title=2016_AMC_8_Problems/Problem_3&oldid=81278"