# 2005 AMC 8 Problems/Problem 22

## Problem

A company sells detergent in three different sized boxes: small (S), medium (M) and large (L). The medium size costs 50% more than the small size and contains 20% less detergent than the large size. The large size contains twice as much detergent as the small size and costs 30% more than the medium size. Rank the three sizes from best to worst buy. $\text{(A)}\, SML \qquad \text{(B)}\, LMS \qquad \text{(C)}\, MSL \qquad \text{(D)}\, LSM \qquad \text{(E)}\, MLS$

## Solution

Suppose the small size costs $\textdollar 1$ and the large size has $10$ oz. The medium size then costs $\textdollar 1.50$ and has $8$ oz. The small size has $5$ oz and the large size costs $\textdollar 1.95$. The small, medium, and large size cost respectively, $0.200, 0.188, 0.195$ dollars per oz. The sizes from best to worst buy are $\boxed{\textbf{(E)}\ \text{MLS}}$.

The problems on this page are copyrighted by the Mathematical Association of America's American Mathematics Competitions. 