Three distinct numbers are selected randomly from the set {1,2,3, …, 40}. If the probability, that the selected numbers are in an increasing G.P., is…

Three distinct numbers are selected randomly from the set $\displaystyle \{1,2,3, \ldots, 40\}$. If the probability, that the selected numbers are in an increasing G.P., is $\displaystyle \frac{\mathrm{m}}{\mathrm{n}}, \operatorname{gcd}(\mathrm{m}, \mathrm{n})=1$, then $\displaystyle \mathrm{m}+\mathrm{n}$ is equal to $\displaystyle \_\_\_\_$.