Since Plant is running faster he’ll meet Page exactly once in his each lap (A to B or B to A) except when they meet at one of the end points. The time taken by Plant to cover 50 meters is same as the time taken by Page to cover 20 metres (as the ratio of their speeds is 5 : 2). After this they will meet at A and this will be their 5lh meeting. After Plant completes 10 laps they will be at their respective original points and would have met 9 times. Similarly after another 10 Laps for Plant they will be at their respective original points and would have met 18 times. (Page will be at A and Plant will be at B.) The 23rd,u meeting will be at A again (23 = 18 + 5) as explained above.