Difference between revisions of "2024 AMC 10B Problems/Problem 21"

(Problem)
(Problem)
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Two straight pipes (circular cylinders), with radii <math>1</math> and <math>\frac{1}{4}</math>, lie parallel and in contact on a flat floor. The figure below shows a head-on view. What is the sum of the possible radii of a third parallel pipe lying on the same floor and in contact with both?
 
Two straight pipes (circular cylinders), with radii <math>1</math> and <math>\frac{1}{4}</math>, lie parallel and in contact on a flat floor. The figure below shows a head-on view. What is the sum of the possible radii of a third parallel pipe lying on the same floor and in contact with both?
  
[asy]
+
<asy>
 
size(6cm);
 
size(6cm);
 
draw(circle((0,1),1), linewidth(1.2));
 
draw(circle((0,1),1), linewidth(1.2));
 
draw((-1,0)--(1.25,0), linewidth(1.2));
 
draw((-1,0)--(1.25,0), linewidth(1.2));
 
draw(circle((1,1/4),1/4), linewidth(1.2));
 
draw(circle((1,1/4),1/4), linewidth(1.2));
[/asy]
+
</asy>
  
<math>\textbf{(A)}~\displaystyle\frac{1}{9}
+
<math>\textbf{(A)}~\frac{1}{9}
 
\qquad\textbf{(B)}~1
 
\qquad\textbf{(B)}~1
\qquad\textbf{(C)}~\displaystyle\frac{10}{9}
+
\qquad\textbf{(C)}~\frac{10}{9}
\qquad\textbf{(D)}~\displaystyle\frac{11}{9}
+
\qquad\textbf{(D)}~\frac{11}{9}
\qquad\textbf{(E)}~\displaystyle\frac{19}{9}</math>
+
\qquad\textbf{(E)}~\frac{19}{9}</math>
  
 
==Solution 1==
 
==Solution 1==

Revision as of 08:32, 14 November 2024

Problem

Two straight pipes (circular cylinders), with radii $1$ and $\frac{1}{4}$, lie parallel and in contact on a flat floor. The figure below shows a head-on view. What is the sum of the possible radii of a third parallel pipe lying on the same floor and in contact with both?

[asy] size(6cm); draw(circle((0,1),1), linewidth(1.2)); draw((-1,0)--(1.25,0), linewidth(1.2)); draw(circle((1,1/4),1/4), linewidth(1.2)); [/asy]

$\textbf{(A)}~\frac{1}{9} \qquad\textbf{(B)}~1 \qquad\textbf{(C)}~\frac{10}{9} \qquad\textbf{(D)}~\frac{11}{9} \qquad\textbf{(E)}~\frac{19}{9}$

Solution 1

See also

2024 AMC 10B (ProblemsAnswer KeyResources)
Preceded by
Problem 20
Followed by
Problem 22
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 10 Problems and Solutions

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