Cover speed as distance per unit time, rearranged to find any of the three, units mph, km/h and m/s, and decimal-hour care (2.4 hours is 2 h 24 min). Single-stage journeys only. Multi-stage averages are average-speed, unit switching is converting-rates, and graph readings sit in the rates-on-graphs group. Both tiers. (R11, R1)