jmc

For positive numbers, the larger the number, the smaller its reciprocal. Likewise, smaller numbers have larger reciprocals. Thus, all we have to do is find the smallest number. But which one is it? $\frac{1}{3}$? or $\frac{2}{5}$? We see that $\frac{1}{3}=\frac{5}{15}$, and $\frac{2}{5}=\frac{6}{15}$, so obviously $\frac{1}{3}$ is smaller. $\boxed{\frac{1}{3}}$