## Elementary Algebra

We need to convert 0.25 miles per 6 seconds into miles per hour. To do this, we multiply 0.25 miles per 6 seconds by the ratio that converts seconds to hours. The ratio that converts seconds to hours is $\frac{3600\ seconds}{1\ hour}$. So, $\frac{0.25\ mile}{6\ seconds}$ $\times$ $\frac{3600\ seconds}{1\ hour}$ = $\frac{900\ miles}{6\ hours}$ = 150 miles per hour.