Quiz Discussion

A gun is fired at a distance of 1.7 km from Ram and he hears the sound after 25 seconds. The speed of sound in meter per second is

• 1] 60 m/s
• 2] 62 m/s
• 3] 64 m/s
• 4] 68 m/s

A is travelling at 72 km per hour on a highway while B is travelling at a speed of 25 mitres per second. What us the difference in their speeds in mitres per second ?

• 1]

  \(1\frac{1}{2} \)m/sec

• 2]

  2 m/sec

• 3]

  3 m/sec

• 4]

  5 m/sec

A car after traveling 18 km from a point A developed some problem in the engine and the speed became \(\frac{4}{5}\) th of its original speed. As a result, the car reached point B 45 minutes late. If the engine had developed the same problem after traveling 30 km from A, then it would have reached 36 minutes late. The original speed of the car (in km/h) is:

• 1] 25 kmph
• 2] 30 kmph
• 3] 20 kmph
• 4] 35 kmph
• 5] None of these

Mr A started half an hour later than usual for the marketplace. But by increasing his speed to \(\frac{3}{2} \)times his usual speed he reached 10 minutes earlier than usual. What is his usual time for this journey?

• 1] 1 hours
• 2] 2 hours
• 3] 3 hours
• 4] 45 minutes
• 5] None of these

Paschim Express left Delhi for Mumbai at 14.30 hrs travelling at a speed of 60 kmph and August Kranti Express left Delhi for Mumbai in the same day at 16.30 hrs travelling at a speed of 80 kmph. How far away from Delhi will the two trains meet (excluding stoppages) ?

• 1] 120 km
• 2] 360 km
• 3] 480 km
• 4] 500 km

A racetrack is in the form of a right triangle. The longer of the legs of track is 2 km more than the shorter of the legs (both these legs being on a highway). The start and end points are also connected to each other through a side road. The escort vehicle for the race took the side road and rode with a speed of 30 km/h and then covered the two intervals along the highway during the same time with a speed of 42 km/h. find the length of the race track.

• 1] 14 km
• 2] 10 km
• 3] 24 km
• 4] 36 km
• 5] 30 km

A car traveling with \(\frac{5}{7}\) of its actual speed covers 42 km in 1 hour 40 minute 48 seconds. Find the actual speed of the car.

• 1]

  \(17\frac{6}{7}\) km/hr

• 2]

  25 km/hr

• 3]

  30 km/hr

• 4]

  35 km/hr

A man walk a certain distance and rides back in 4 hours 30 minutes. He could ride both ways in 3 hours. The time required by the man to walk both ways is :

• 1] 4 hours 30 minutes
• 2] 4 hours 45 minutes
• 3] 5 hours
• 4] 6 hours

In a 1-kilometre race, A can beat B by 30 meters, while in a 500-meter race B can beat C by 25 meters. By how many meters will A beats C in a 100-meter race?

• 1] 7.85
• 2] 7.25
• 3] 7.15
• 4] 7.03

A train travelling at 48 kmph crosses another train, having half of its length and travelling in opposite direction at 42 kmph, in 12 seconds. It also passes a railway platform in 45 seconds. The length of railway platform is:

• 1] 200m
• 2] 300m
• 3] 350m
• 4] 400m