a) \(\frac{2}{20}\) \(\cdot\) 4 = \(\frac{2}{20}\) + \(\frac{2}{20}\) + \(\frac{2}{20}\) + \(\frac{2}{20}\) = \(\frac{8}{20}\) = \(\frac{2}{5}\)
Ответ: \(\frac{2}{5}\)