A cross country skier reaches the 3km mark of a race in 15 min and 12 km mark 45 min later. Assuming a contrast rate find the speed of the skier

To find the speed you must write S = d/t so for the first one we will chang 15 m to b so it is = 0.25h so s=3/0.25h = 12km/h an why secand is 45 m to h = 0.75h so S=d/t S = 12/0.75 = 16 km/h the to find the totel speed we should + the speed together so 12 + 16 = 28 km/h