Mr thiru took 1h to drive frm A to B at an average speed of 60Km/h. after taking a rest, he travelled 60km to reach C. His overall average speed was 36km/h. If he left A at 10.50a.m. at What time did he reach C

From A to B he travelled 60 km. From B to C he also travelled 60 km. I will assume that his "overall average" speed was reduced by the period of rest. The total time for the trip would then be
120 km/(36 km/h) = 3 1/3 hours. For the time of arrival, add 3 h 20 min to 10:50 AM.