Art of Problem Solving

2025 AMC 10A Problems/Problem 2: Difference between revisions

Cheltstudent (talk | contribs)
No edit summary
Stevens0209 (talk | contribs)
No edit summary
Line 1: Line 1:
A box contains <imath>10</imath> pounds of a nut mix that is <imath>50</imath> percent peanuts, <imath>20</imath> percent cashews, and <imath>30</imath> percent almonds. A second nut mix containing <imath>20</imath> percent peanuts, <imath>40</imath> percent cashews, and <imath>40</imath> percent almonds is added to the box resulting in a new nut mix that is <imath>40</imath> percent peanuts. How many poiunds of cashews are now in the box?
A box contains <imath>10</imath> pounds of a nut mix that is <imath>50</imath> percent peanuts, <imath>20</imath> percent cashews, and <imath>30</imath> percent almonds. A second nut mix containing <imath>20</imath> percent peanuts, <imath>40</imath> percent cashews, and <imath>40</imath> percent almonds is added to the box resulting in a new nut mix that is <imath>40</imath> percent peanuts. How many pounds of cashews are now in the box?


<imath>\textbf{(A)}~3.5\qquad\textbf{(B)}~4\qquad\textbf{(C)}~4.5\qquad\textbf{(D)}~5\qquad\textbf{(E)}~6</imath>
<imath>\textbf{(A)}~3.5\qquad\textbf{(B)}~4\qquad\textbf{(C)}~4.5\qquad\textbf{(D)}~5\qquad\textbf{(E)}~6</imath>
==Solution 1==
We have <cmath>5</cmath> pounds of peanuts, <cmath>2</cmath> pounds of cashews, and <cmath>3</cmath> pounds of almonds in the first nut mix.
Let there be <cmath>x</cmath> pounds of nuts in the second nut mix, thus we have <cmath>0.2x</cmath> worth of peanuts. That means:
<cmath>\(\frac{5 + 0.2x}{10 + x} = 0.4\)</cmath>
<cmath>5+0.2x=0.4(10+x)
5+0.2x=4+0.4x
1=0.2x
x=5</cmath>
That means we have 5 pounds of the second nut mix. We are trying to find the amount of cashews in pounds.
<cmath>10*0.2+5*0.4=2+2=4</cmath>
There are a total of <cmath>\fbox{\textbf{(B)} 4}</cmath>

Revision as of 13:17, 6 November 2025

A box contains $10$ pounds of a nut mix that is $50$ percent peanuts, $20$ percent cashews, and $30$ percent almonds. A second nut mix containing $20$ percent peanuts, $40$ percent cashews, and $40$ percent almonds is added to the box resulting in a new nut mix that is $40$ percent peanuts. How many pounds of cashews are now in the box?

$\textbf{(A)}~3.5\qquad\textbf{(B)}~4\qquad\textbf{(C)}~4.5\qquad\textbf{(D)}~5\qquad\textbf{(E)}~6$

Solution 1

We have \[5\] pounds of peanuts, \[2\] pounds of cashews, and \[3\] pounds of almonds in the first nut mix.

Let there be \[x\] pounds of nuts in the second nut mix, thus we have \[0.2x\] worth of peanuts. That means:

\[\(\frac{5 + 0.2x}{10 + x} = 0.4\)\] (Error compiling LaTeX. Unknown error_msg)

\[5+0.2x=0.4(10+x) 5+0.2x=4+0.4x 1=0.2x x=5\]

That means we have 5 pounds of the second nut mix. We are trying to find the amount of cashews in pounds.

\[10*0.2+5*0.4=2+2=4\]


There are a total of \[\fbox{\textbf{(B)} 4}\]