2. Two pieces of cheese have the shape of a rectangular parallelepiped each. The length of the first piece is $50\%$ greater than the length of the second piece, while the width and height of the first piece are $20\%$ and $30\%$ less than the width and height of the second piece, respectively. Which piece of cheese has a larger volume and by how much?
Answer: The second one is $19 \frac{1}{21} \%$ more (the first one is $16 \%$ less).

Solution. Let $a, b$ and $c$ be the length, width, and height of the second piece of cheese, respectively. Then its volume is $V_{2}=a b c$. According to the problem, the volume of the first piece of cheese is $V_{1}=\frac{3}{2} a \cdot \frac{4}{5} b \cdot \frac{7}{10} c=\frac{84}{100} V_{2}$. Therefore, $V_{2}=\frac{25}{21} V_{1}=1 \frac{4}{21} V_{1}$, and $\frac{4}{21}=19 \frac{1}{21} \%$.