Difference between revisions of "1957 AHSME Problems/Problem 30"

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== Solution ==
 
== Solution ==
<math>\boxed{\textbf{(D) }1 \text{ and } 1}</math>.
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When <math>n=1</math>, the value of the given expression must be <math>1^2=1</math>. Plugging in the values given by the answer choices, we see that the only option that returns <math>1</math> when <math>n=1</math> is <math>\boxed{\textbf{(D) }1 \text{ and } 1}</math>.
  
 
== See Also ==
 
== See Also ==

Latest revision as of 17:07, 25 July 2024

Problem

The sum of the squares of the first n positive integers is given by the expression $\frac{n(n + c)(2n + k)}{6}$, if $c$ and $k$ are, respectively:

$\textbf{(A)}\ {1}\text{ and }{2} \qquad \textbf{(B)}\ {3}\text{ and }{5}\qquad \textbf{(C)}\ {2}\text{ and }{2}\qquad\textbf{(D)}\ {1}\text{ and }{1}\qquad\textbf{(E)}\ {2}\text{ and }{1}$

Solution

When $n=1$, the value of the given expression must be $1^2=1$. Plugging in the values given by the answer choices, we see that the only option that returns $1$ when $n=1$ is $\boxed{\textbf{(D) }1 \text{ and } 1}$.

See Also

1957 AHSC (ProblemsAnswer KeyResources)
Preceded by
Problem 29
Followed by
Problem 31
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