A cyclist leaves his training base for a morning workout, riding at the rate of 18mph. one hour later his support staff leaves the base in a car going 45mph in the same direction. How long will it take the support staff to catch up with the cyclist?

The support staff has to make up a lead distance of 18 km. How long will that take then if they make up distance at a rate of 45 - 18 = 27 mph?