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2005 AMC 8 Problems/Problem 5

Revision as of 16:23, 29 July 2011 by Math Kirby (talk | contribs) (→‎Problem 5)

Problem

If $20\%$ of a number is $12$, what is $30\%$ of the same number?

$\mathrm{(A)}\ 15\qquad\mathrm{(B)}\ 18 \qquad\mathrm{(C)}\ 20 \qquad\mathrm{(D)}\ 24 \qquad\mathrm{(E)}\ 30$

Solution

Since $20 \%$ of a number is $12$, then $10 \%$ of the number is $6$, so $30\%$ of the number is $\boxed{\mathrm{(B)}\ 18}$.

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