\[\boxed{\mathbf{2.438}}\]
\[\textbf{а)}\ верно:\]
\[15 \cdot 2\frac{1}{5} = 15 \cdot 2 + 15 \cdot \frac{1}{5} =\]
\[= 30 + 3 = 33.\]
\[\textbf{б)}\ верно:\]
\[24 \cdot 4\frac{1}{4} = 24 \cdot 4 + 24 \cdot \frac{1}{4} =\]
\[= 96 + 6 = 102.\]
\[\textbf{в)}\ неверно:\]
\[36 \cdot \frac{2}{3} = 36 \cdot \left( 1 - \frac{1}{3} \right) =\]
\[= 36 - 36\ :3 = 36 - 12 = 24.\]
\[\textbf{г)}\ верно:\]
\[98 \cdot \frac{6}{7} = 98 \cdot \left( 1 - \frac{1}{7} \right) =\]
\[= 98 \cdot 1 - 98\ :7 = 98 - 14 =\]
\[= 84.\]