$$\frac{3}{5} (b + p) + \frac{1}{15} = \frac{2}{3}\\\\frac{3}{5} (b + p) = \frac{2}{3} - \frac{1}{15}\\\\frac{3}{5} (b + p) = \frac{10}{15} - \frac{1}{15}\\\\frac{3}{5} (b + p) = \frac{9}{15}\\\\frac{3}{5} (b + p) = \frac{3}{5}\\\$$b + p = \frac{3}{5} \div \frac{3}{5}\\\$$b + p = 1$$
Ответ: 1