[tex] \frac{1}{5} + \frac{1}{10} + \frac{1}{30} = \\ \\ \frac{1}{5} + \frac{1}{10} = \frac{1 \times 2}{5 \times 2} + \frac{1}{10} = \frac{2}{10} + \frac{1}{10} = \frac{2 + 1}{10} = \frac{3}{10} \\ \\ \frac{3}{10} + \frac{1}{30} = \frac{3 \times 3}{10 \times 3} + \frac{1}{30} = \frac{9}{30} + \frac{1}{30} = \frac{9 + 1}{30} = { \frac{10}{30} }^{(10} = \frac{1}{3} [/tex]
