Difference between revisions of "1950 AHSME Problems/Problem 33"

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\textbf{(E)}\ 36\pi</math>
 
\textbf{(E)}\ 36\pi</math>
 
==Solution==
 
==Solution==
{{solution}}
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It must be assumed that the pipes have an equal height.
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A circular pipe with diameter 1 inch and height h has a volume of <math>\pi (\frac{1}{2})^2h=\frac{\pi h}{4}</math>. A pipe with diameter 6 inches and height h has volume <math>\pi (\frac{6}{2})^2h=9\pi h</math>. To find how many 1-pipes fit in a 6-pipe, we divide: <math>\frac{9\pi h}{\frac{\pi h}{4}}=\frac{9*4\pi h}{\pi h}=\frac{36\pi h}{\pi h}=36 \text{(D)}</math>
  
 
==See Also==
 
==See Also==

Revision as of 14:06, 5 July 2012

Problem

The number of circular pipes with an inside diameter of $1$ inch which will carry the same amount of water as a pipe with an inside diameter of $6$ inches is:

$\textbf{(A)}\ 6\pi \qquad \textbf{(B)}\ 6 \qquad \textbf{(C)}\ 12 \qquad \textbf{(D)}\ 36 \qquad \textbf{(E)}\ 36\pi$

Solution

It must be assumed that the pipes have an equal height.

A circular pipe with diameter 1 inch and height h has a volume of $\pi (\frac{1}{2})^2h=\frac{\pi h}{4}$. A pipe with diameter 6 inches and height h has volume $\pi (\frac{6}{2})^2h=9\pi h$. To find how many 1-pipes fit in a 6-pipe, we divide: $\frac{9\pi h}{\frac{\pi h}{4}}=\frac{9*4\pi h}{\pi h}=\frac{36\pi h}{\pi h}=36 \text{(D)}$

See Also

1950 AHSC (ProblemsAnswer KeyResources)
Preceded by
Problem 32
Followed by
Problem 34
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All AHSME Problems and Solutions