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

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==Solution==
 
==Solution==
First of all, <math>0.000000375 = 3.75 \times 10^{-7}</math> in scientific notation. This eliminates <math>\textbf{(A)}\ 3.75\times 10^{-7}</math>, <math>\textbf{(B)}\ 3\frac{3}{4}\times 10^{-7}</math>, and <math>\textbf{(C)}\ 375\times 10^{-9}</math> immediately. <math>\textbf{(E)}\ \frac{3}{80000000}</math> is a bit harder, but it can be rewritten as <math>\frac{3}{8} \cdot 10^{-7}</math>, which is the same as <math>3.75 \times 10^{-7}</math>, so the answer is  <math>\textbf{(D)}\ \frac{3}{8}\times 10^{-7}</math>.
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First of all, <math>0.000000375 = 3.75 \times 10^{-7}</math> in scientific notation. This eliminates <math>\textbf{(A)}\ 3.75\times 10^{-7}</math>, <math>\textbf{(B)}\ 3\frac{3}{4}\times 10^{-7}</math>, and <math>\textbf{(C)}\ 375\times 10^{-9}</math> immediately. <math>\textbf{(E)}\ \frac{3}{80000000}</math> is a bit harder, but it can be rewritten as <math>\frac{3}{8} \cdot 10^{-7}</math>, which is the same as <math>3.75 \times 10^{-7}</math>, so the answer is  \boxed{(A) 3.75\times 10^{-7}}
 
 
 
==See Also==
 
==See Also==
  

Revision as of 17:37, 29 April 2017

Problem

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

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

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 $\frac{3}{8} \cdot 10^{-7}$, which is the same as $3.75 \times 10^{-7}$, so the answer is \boxed{(A) 3.75\times 10^{-7}}

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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