Difference between revisions of "1955 AHSME Problems/Problem 1"

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Which one of the following is not equivalent to <math>0.000000375</math>?  
 
Which one of the following is not equivalent to <math>0.000000375</math>?  
  
<math> \textbf{(A)}\ 3.75\times 10^{-7}\qquad\textbf{(B)}\ 3\frac{3}{4}\times 10^{-7}\qquad\textbf{(C)}\ 375\times 10^{-9}\\ \textbf{(D)}\ \frac{3}{8}\times 10^{-7}\qquad\textbf{(E)}\ \frac{3}{80000000} </math>  
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<math> \textbf{(A)}\ 3.75\times 10^{-7}\qquad\textbf{(B)}\ 3\frac{3}{4}\times 10^{-7}\qquad\textbf{(C)}\ 375\times 10^{-9}\qquad \textbf{(D)}\ \frac{3}{8}\times 10^{-7}\qquad\textbf{(E)}\ \frac{3}{80000000} </math>
  
 
==Solution==
 
==Solution==

Revision as of 14:52, 21 February 2019

Problem

Which one of the following is not equivalent to $0.000000375$?

$\textbf{(A)}\ 3.75\times 10^{-7}\qquad\textbf{(B)}\ 3\frac{3}{4}\times 10^{-7}\qquad\textbf{(C)}\ 375\times 10^{-9}\qquad \textbf{(D)}\ \frac{3}{8}\times 10^{-7}\qquad\textbf{(E)}\ \frac{3}{80000000}$

Solution

First of all, $0.000000375 = 3.75 \times 10^{-7}$ in scientific notation. This eliminates $\textbf{(A)}\ 3.75\times 10^{-7}$, $\textbf{(B)}\ 3\frac{3}{4}\times 10^{-7}$, and $\textbf{(C)}\ 375\times 10^{-9}$ immediately. $\textbf{(E)}\ \frac{3}{80000000}$ is a bit harder, but it can be rewritten as $\frac{3}{8} \cdot 10^{-7}$. Thus, as entered, the answer is $\boxed{\mathrm{(D) \frac{3}{8} \times 10^{-7}}}$ and $\boxed{\mathrm{(E)} \frac{3}{80000000}}$

See Also

1955 AHSC (ProblemsAnswer KeyResources)
Preceded by
First Question
Followed by
Problem 2
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All AHSME Problems and Solutions


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