Difference between revisions of "2022 AMC 8 Problems/Problem 15"

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dot((2.5,4.4),black);
 
dot((2.5,4.4),black);
  
dot((3,2.5),black);
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dot((3,2.5),blue);
 
dot((3,3.4),black);
 
dot((3,3.4),black);
 
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dot((3,4.2),black);

Revision as of 17:24, 28 January 2022

Problem

Laszlo went online to shop for black pepper and found thirty different black pepper options varying in weight and price, shown in the scatter plot below. In ounces, what is the weight of the pepper that offers the lowest price per ounce?

[asy] //diagram by pog size(5.5cm); usepackage("mathptmx"); defaultpen(mediumgray*0.5+gray*0.5+linewidth(0.63)); add(grid(6,6)); label(scale(0.7)*"$1$", (1,-0.3), black); label(scale(0.7)*"$2$", (2,-0.3), black); label(scale(0.7)*"$3$", (3,-0.3), black); label(scale(0.7)*"$4$", (4,-0.3), black); label(scale(0.7)*"$5$", (5,-0.3), black); label(scale(0.7)*"$1$", (-0.3,1), black); label(scale(0.7)*"$2$", (-0.3,2), black); label(scale(0.7)*"$3$", (-0.3,3), black); label(scale(0.7)*"$4$", (-0.3,4), black); label(scale(0.7)*"$5$", (-0.3,5), black); label(scale(0.75)*rotate(90)*"Price (dollars)", (-1,3.2), black); label(scale(0.75)*"Weight (ounces)", (3.2,-1), black); dot((1,1.2),black); dot((1,1.7),black); dot((1,2),black); dot((1,2.8),black);  dot((1.5,2.1),black); dot((1.5,3),black); dot((1.5,3.3),black); dot((1.5,3.75),black);  dot((2,2),black); dot((2,2.9),black); dot((2,3),black); dot((2,4),black); dot((2,4.35),black); dot((2,4.8),black);  dot((2.5,2.7),black); dot((2.5,3.7),black); dot((2.5,4.2),black); dot((2.5,4.4),black);  dot((3,2.5),blue); dot((3,3.4),black); dot((3,4.2),black);  dot((3.5,3.8),black); dot((3.5,4.5),black); dot((3.5,4.8),black);  dot((4,3.9),black); dot((4,5.1),black);  dot((4.5,4.75),black); dot((4.5,5),black);  dot((5,4.5),black); dot((5,5),black); [/asy]

$\textbf{(A) }1\qquad\textbf{(B) }2\qquad\textbf{(C) }3\qquad\textbf{(D) }4\qquad\textbf{(E) }5$

Solution

We are looking for a black point, that when connected to the origin, yields the lowest slope. The slope represents the price per ounce. It is clearly the blue point, which can be found visually. Also, it is the only one with a price per once significantly less than $1$. Finally, we see that the blue point is over the category with a weight of $\boxed{\textbf{(C) } 3}$ ounces.

~MathFun1000

See Also

2022 AMC 8 (ProblemsAnswer KeyResources)
Preceded by
Problem 14
Followed by
Problem 16
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 AJHSME/AMC 8 Problems and Solutions

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