\[5^{- 2} + \left( \frac{10}{3} \right)^{- 1} = \frac{1}{5^{2}} + \frac{3}{10} = \frac{1^{\backslash 2}}{25} + \frac{3^{\backslash 5}}{10} =\]
\[= \frac{2 + 15}{50} = \frac{17}{50}\]