The question of real numbers exercise 1.2. The question no.7 is the most important question of class 10th. I want to solve this question by best method. Please help me for solving this question. There is a circular path around a sports field. Sonia takes 18 minutes to drive one round of the field, while Ravi takes 12 minutes for the same. Suppose they both start at the same point and at the same time, and go in the same direction. After how many minutes will they meet again at the starting point?