Art of Problem Solving

2025 AMC 10A Problems/Problem 1: Difference between revisions

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== Problem ==
== Problem ==


Andy and Betsy both live in Mathville. Andy leaves Mathville on his bicycle at <imath>1:30</imath>, traveling due northat a steady <imath>8</imath> mile per hour. Betsy leaves on her bicycle from the same point at <imath>2:30</imath>, traveling due east at a steady <imath>12</imath> miles per hour. At what time will thy be exactly the same distance from their common starting point?
Andy and Betsy both live in Mathville. Andy leaves Mathville on his bicycle at <imath>1:30</imath>, traveling due northat a steady <imath>8</imath> mile per hour. Betsy leaves on her bicycle from the same point at <imath>2:30</imath>, traveling due east at a steady <imath>12</imath> miles per hour. At what time will they be exactly the same distance from their common starting point?


<imath>\textbf{(A) } {3:30}\qquad\textbf{(B) } {3:45}\qquad\textbf{(C) } {4:00}\qquad\textbf{(D) } {4:15}\qquad\textbf{(E) } {4:30}</imath>
<imath>\textbf{(A) } {3:30}\qquad\textbf{(B) } {3:45}\qquad\textbf{(C) } {4:00}\qquad\textbf{(D) } {4:15}\qquad\textbf{(E) } {4:30}</imath>


== Solution==
== Solution==

Revision as of 12:44, 6 November 2025

Problem

Andy and Betsy both live in Mathville. Andy leaves Mathville on his bicycle at $1:30$, traveling due northat a steady $8$ mile per hour. Betsy leaves on her bicycle from the same point at $2:30$, traveling due east at a steady $12$ miles per hour. At what time will they be exactly the same distance from their common starting point?

$\textbf{(A) } {3:30}\qquad\textbf{(B) } {3:45}\qquad\textbf{(C) } {4:00}\qquad\textbf{(D) } {4:15}\qquad\textbf{(E) } {4:30}$

Solution

We can see that Betsy travles 1 hour after Andy started. We have $lcm(8, 12)=24$ now we can find the time traveled \(\frac{24}{8} = 3 \text{ hours}\)

Now we have time \(1{:}30 + 3{:}00 = \boxed{\textbf{(E) } 4{:}30}\)

-Boywithnuke(Goal: 10 followers)