A car travels 23 1/2 miles in 3/5 of an hour. What is the car's rate in miles per hour?

$23\frac{1}{2}:\frac{3}{5}=39\frac{1}{6}$mph

(23 1/2) / (3/5) =(23 1/2) x (5/3) =47/2 x 5/3 =235/6 =39 1/6 mph.