Consider the question. A man intends to complete a journey of 24 km in 8 hours. If he travels at a speed of 4km/hr for the first four hours, at what speed does he need to travel for the remainder of the journey to be right on time?
 What is the step-by-step reasoning process to arrive at the answer: 2?
He covers 4km / hr * 4hrs = 16km in the first 4 hours. He has 24 - 16 = 8km left to cover. He has 8 - 4 = 4 hours to cover the remaining 8km. He has to travel at a speed of 8km / 4hrs = 2km / hr to be right on time.