A. 11 km/hr

B. 12 km/hr

C. 13 km/hr

D. 14 km/hr

There are 5 duplicating machines in an office. The fastest of the machines makes P copies in 10 hours and the slowest of the machines makes P copies in 11 hours. If each machine makes P copies then the average time per machine cannot be

Two stations P and Q are 110 km apart on a straight track. One train starts from P at 7 a.m. and travels towards Q at 20 kmph. Another train starts from Q at 8 a.m. and travels towards P at a speed of 25 kmph. At what time will they meet?

A train 360 m long runs with a speed of 45 km/hr. What time will it take to pass a platform of 140 m long?

A truck covers a distance of 550 metres in 1 minute whereas a train covers a distance of 33 kms in 45 minutes. What is the ratio of their speed?

A boat goes 13 km upstream in 39 minutes. The speed of stream is 3 km/hr. The speed of boat in still water is: