Difference between revisions of "2017 AMC 12B Problems/Problem 1"

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==Solution==
 
==Solution==
  
Kymbrea has <math>30</math> comic books initially and every month, she adds two. This can be represented as <math>30 + 2x</math> where x is the number of months elapsed. LaShawn's collection, similarly, is <math>10 + 6x</math>. To find when they will have an equal amount, we solve x for <math>2x + 30 = 6x + 10</math> and get <math>x = 5</math> <math>\boxed{\textbf{C}}</math>.
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Kymbrea has <math>30</math> comic books initially and every month, she adds two. This can be represented as <math>30 + 2x</math> where x is the number of months elapsed. LaShawn's collection, similarly, is <math>10 + 6x</math>. To find when LaShawn will have twice the number of comic books as Kymbrea, we solve for x with the equation <math>2(2x + 30) = 6x + 10</math> and get <math>x = 25</math> <math>\boxed{\textbf{E}}</math>.
  
 
==See Also==
 
==See Also==
 
{{AMC12 box|year=2017|ab=B|before=First Problem|num-a=2}}
 
{{AMC12 box|year=2017|ab=B|before=First Problem|num-a=2}}
 
{{MAA Notice}}
 
{{MAA Notice}}

Revision as of 18:46, 16 February 2017

Problem 1

Kymbrea's comic book collection currently has $30$ comic books in it, and she is adding to her collection at the rate of $2$ comic books per month. LaShawn's collection currently has $10$ comic books in it, and he is adding to his collection at the rate of $6$ comic books per month. After how many months will LaShawn's collection have twice as many comic books as Kymbrea's?

$\textbf{(A)}\ 1\qquad\textbf{(B)}\ 4\qquad\textbf{(C)}\ 5\qquad\textbf{(D)}\ 20\qquad\textbf{(E)}\ 25$

Solution

Kymbrea has $30$ comic books initially and every month, she adds two. This can be represented as $30 + 2x$ where x is the number of months elapsed. LaShawn's collection, similarly, is $10 + 6x$. To find when LaShawn will have twice the number of comic books as Kymbrea, we solve for x with the equation $2(2x + 30) = 6x + 10$ and get $x = 25$ $\boxed{\textbf{E}}$.

See Also

2017 AMC 12B (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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