For $\mathrm{x}>0,$ if ${\mathrm{p}}^{\mathrm{th}}$ term is the first negative term in the expansion of ${\left(1+\frac{3\mathrm{x}}{5}\right)}^{22/3}$ and in the expansion of ${\left(1-\frac{3\mathrm{x}}{5}\right)}^{22/3}$ from ${\mathrm{r}}^{\mathrm{th}}$ term onwards all the terms are positive, then the number of terms in the expansion of ${\left(\mathrm{px}+\frac{\mathrm{r}}{\mathrm{x}}\right)}^{\mathrm{pr}}$ is $\mathrm{\_\_\_\_}$