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
