A6 If the edge of a cube $a$ is reduced by $50 \%$, what is the volume of the new, reduced cube, in comparison to the original?
(A) $50 \%$ of the original volume
(B) $25 \%$ of the original volume
(C) $12.5 \%$ of the original volume
(D) $6.25 \%$ of the original volume
(E) $7.5 \%$ of the original volume
A6. The volume of the reduced cube $V_{1}$ is expressed in terms of the original volume $V=a^{3}$. Thus, $V_{1}=$ $\left(\frac{a}{2}\right)^{3}=\frac{1}{8} V=12.5 \% V$.

## Group B