2005 AMC 12B Problems/Problem 3

Revision as of 22:13, 17 April 2009 by M1sterzer0 (talk | contribs) (Solution)

Problem

Brianna is using part of the money she earned on her weekend job to buy several equally-priced CDs. She used one fifth of her money to buy one third of the CDs. What fraction of her money will she have left after she buys all the CDs?

$\mathrm{(A)}\ \frac15      \qquad \mathrm{(B)}\ \frac13      \qquad \mathrm{(C)}\ \frac25      \qquad \mathrm{(D)}\ \frac23      \qquad \mathrm{(E)}\ \frac45$

Solution

Let $m=$Brianna's money. We have $\frac15 m = \frac13 (\mbox{CDs}) \Rightarrow \frac35 m = (\mbox{CDs})$. Thus, the money left over is $m-\frac35m = \frac25m$, so the answer is $\boxed{\frac25}$.

See also