jmc

If $x$ is the number, then $2x=60$ and $x=30$. Dividing the number by $2$ yields $\frac{30}{2}=\boxed{\text{(B)}15}$. A second way to do it is to divide the number by $4$, as you multiplied by $2$ when you were supposed to divide by $2$. So, $\frac{60}{4}=\boxed{15}$.