2. а) (4 8/15 − 1 1/3) · 15/64; б) (68,32 − 13,23) : 0,25;

а) \(4\frac{8}{15}-1\frac{1}{3}=\frac{68}{15}-\frac{20}{15}=\frac{48}{15}=\frac{16}{5}\).

\(\frac{16}{5}\cdot\frac{15}{64}=\frac{3}{4}\).

б) \((68.32-13.23):0.25=55.09:0.25=220.36\).

Ответ: а) \(\frac{3}{4}\); б) \(220,36\).