2016 AMC 8 Problems/Problem 3: Difference between revisions
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==Solution== | ==Solution== | ||
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>\boxed{\textbf{(A) }40}</math> | 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>\boxed{\textbf{(A) }40}</math>. | ||
Revision as of 08:44, 23 November 2016
3. Four students take an exam. Three of their scores are 
and 
. If the average of their four scores is 
, then what is the remaining score?
Solution
We see that 
and 
. We then find that 
. We want our average to be , so we find 
. So our final answer is 
.
