A. 8hrs

B. 4hrs

C. 3hrs

D. none of these

Mary jogs 9 km at a speed of 6 km per hour. At what speed would she need to jog during the next 1.5 hours to have an average of 9 km per hour for the entire jogging session?

The length of the bridge which a train, 130 metres long and travelling at 45 km per hour, can cross in 30 seconds, is

Excluding stoppages, the speed of a bus is 54 kmph and including stoppages, it is 45 kmph. For how many minutes does the bus stop per hour?

The jogging track in a sports complex is 726 metres in circumference. Deepak and his wife start from the same point and walk in opposite directions at 4.5 km/hr and 3.75 km/hr respectively. They will meet for the first time in:

Sakshi can do a piece of work in 20 days. Tanya is 25% more efficient tha Sakshi. The number of days taken by Tanya to do the same piece of work is