Anna went from home to school with the speed 3 km/hour. She ran back home with the speed 6 km/hour.Her sister Olga went to school and back with the same speed, and she spent as much time on the road as Anna. What was Olga's speed?
Let: v = Olga's speed t = the time Anna spent going to school (3 km/hour) t/2 = the time Anna spent running back home with speed of 6 km/hour So, t + t/2 = 3t/2 is the total time In the meantime distance = speed*time and the both made the same distance we can put it as: 3t + 6*(t/2) = (3t/2)*v 6t = (3/2)tv divide both sides by t (3/2)v = 6 v = 2*6/3 v = 4 km/hour Olga's speed was 4 km/hour.
