Difference between revisions of "2020 AMC 12A Problems/Problem 1"

(Video Solution)
(Video Solution)
Line 20: Line 20:
  
 
~IceMatrix
 
~IceMatrix
 
Direct BBCode link:
 
[youtube]https://youtu.be/qJF3G7_IDgc[/youtube]
 
 
~cw357
 
  
 
==See Also==
 
==See Also==

Revision as of 12:25, 28 May 2020

Problem

Carlos took $70\%$ of a whole pie. Maria took one third of the remainder. What portion of the whole pie was left?

$\textbf{(A)}\ 10\%\qquad\textbf{(B)}\ 15\%\qquad\textbf{(C)}\ 20\%\qquad\textbf{(D)}\ 30\%\qquad\textbf{(E)}\ 35\%$

Solution 1

If Carlos took $70\%$ of the pie, $(100 - 70) = 30\%$ must be remaining. After Maria takes $\frac{1}{3}$ of the remaining $30\%,$ $1 - \frac{1}{3} = \frac{2}{3}$ is left.

Therefore:

$30\% \cdot \frac{2}{3} = \boxed{\textbf{C) }20\%}$

-Contributed by Awesome2.1, latex by quacker88

Video Solution

https://youtu.be/qJF3G7_IDgc

~IceMatrix

See Also

2020 AMC 12A (ProblemsAnswer KeyResources)
Preceded by
First Problem
Followed by
Problem 2
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 12 Problems and Solutions

The problems on this page are copyrighted by the Mathematical Association of America's American Mathematics Competitions. AMC logo.png