Two ferries start moving toward each other from opposite riverbanks, a and b. when they pass each other for the first time, the distance to riverbank b is 100 meters. each ferry starts its return trip as soon as it reaches its destination. when the ferries meet for the second time, the distance to riverbank A is 50 meters. what is the distance between riverbanks a and b? Help I will give 40 points. It says the answer is Not 150 nor 50.