A man on tour travels first 160 km at 64 km/hr and the next 160 km at 80 km/hr. The average speed for the first 320 km of the tour is:
Taps A and B can independently fill a tank in 6 and 10 hours . Leak C can empty a filled tank in 8 hours. On an empty tank A, B, C are opened. How long does it take to fill the tank
A thief steals a car at 2.30 p.m. and drives it at 60 kmph. The theft is discovered at 3 p.m. and the owner sets off in another car at 75 kmph. When will he overtake the thief?
A train 108 m long moving at a speed of 50 km/hr crosses a train 112 m long coming from opposite direction in 6 sec. the speed of the sec train is
Two trains, one from Howrah to Patna and other from Patna to Howrah, start simultaneously. After they meet, the trains reach their destinations after 9 hours and 16 hours respectively. The ratio of their speeds is