Walking (6/7)th of his usual speed, a man is 12 minutes too late. The usual time taken by him to cover that distance is:
Answer: A. 1 hr 12 min
New speed = (6/7) of usual speed. New time = (7/6) of usual time. Therefore (7/6 of usual time)- (usual time) = (1/5) hr. => (1/6 of usual time)= (1/5) hr => usual time = (6/5) hr = 1 hr 12 min.