## Elementary Algebra

To express the speed in miles per hour, we need to multiply it by the ratio that converts kilometers to miles. The ratio that converts kilometers to miles is : $\frac{0.62\ mile}{1\ kilometer}$ $\frac{160\ kilometers}{hour}$ $\times$ $\frac{0.62\ mile}{1\ kilometer}$ = $\frac{160\ \times\ 0.62mile}{hour}$ = $\frac{99.2\ miles}{hour}$ = 99.2 miles per hour The top speed of his car is 99.2 miles per hour.