2018 AMC 12A Problems/Problem 1: Difference between revisions
Created page with "==Problem== A large urn contains <math>100</math> balls, of which <math>36 \%</math> are red and the rest are blue. How many of the blue balls must be removed so that the per..." |
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<math> \textbf{(A)}\ 28 \qquad\textbf{(B)}\ 32 \qquad\textbf{(C)}\ 36 \qquad\textbf{(D)}\ | <math> \textbf{(A)}\ 28 \qquad\textbf{(B)}\ 32 \qquad\textbf{(C)}\ 36 \qquad\textbf{(D)}\ | ||
50 \qquad\textbf{(E)}\ 64 </math> | 50 \qquad\textbf{(E)}\ 64 </math> | ||
==Solution== | |||
There are <math>36</math> red balls; for these red balls to comprise <math>72 \%</math> of the urn, there must be only <math>14</math> blue balls. Since there are currently <math>64</math> blue balls, this means we must remove <math>50 = \boxed{ \textbf{(D)}}</math> | |||
Revision as of 13:30, 8 February 2018
Problem
A large urn contains 
balls, of which 
are red and the rest are blue. How many of the blue balls must be removed so that the percentage of red balls in the urn will be 
? (No red balls are to be removed.)
Solution
There are 
red balls; for these red balls to comprise of the urn, there must be only 
blue balls. Since there are currently 
blue balls, this means we must remove 
