Walking 6/7th of his usual speed, a man is 12 minutes too late. The usual time taken by him to cover that distance is :
A). 1 hour
B). 1 hour 12 min.
C). 1 hour 15 min
D). 1 hour 20 min.
1 hour 12 min.
New speed = 6/7 of usual speed.
New time = 7/6 of usual time.
(7/6 of usual time) - (usual time) = 1/5 hour.
Therefore, 1/6 of usual time = 1/5 hour
Usual time = 6/5 hours = 1 hour 12 min.