\[15a \cdot b^{2}a = 15a^{2}b^{2};\]
\[a = \frac{1}{3};\ \ b = 6:\]
\[15 \cdot \left( \frac{1}{3} \right)^{2} \cdot 6^{2} = 15 \cdot \frac{1}{9} \cdot 36 =\]
\[= 15 \cdot 4 = 60.\]