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

(Solution)
(Solution)
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==Solution==
 
==Solution==
  
If Carlos took 70% of the pie, 30% must be remaining. After Maria takes 1/3 of the remaining 30%, meaning that 2/3 is left.
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If Carlos took 70% of the pie, (100 - 70) = 30% must be remaining. After Maria takes 1/3 of the remaining 30%,  
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(1 - 1/3) = 2/3 is left.
  
 
Therefore:
 
Therefore:
  
(3 / 10) * (2 / 3) = (2 / 10) = 20%
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(3 / 10) * (2 / 3) = (2 / 10) = 20%, which is answer choice
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If anyone could add the latex to the numbers / expressions that would be really helpful!
 +
 
 +
-Contributed by Awesome2.1
  
 
==See Also==
 
==See Also==

Revision as of 10:33, 1 February 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

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

Therefore:

(3 / 10) * (2 / 3) = (2 / 10) = 20%, which is answer choice

If anyone could add the latex to the numbers / expressions that would be really helpful!

-Contributed by Awesome2.1

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

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