Quiz Discussion

A train running at a speed of 54 km/hr crosses a platform in 30 seconds. The platform is renovated and its length is doubled. Now, the same train running at same speed crosses the platform in 46 seconds. Find the length of the train.

• 1] 180 metres
• 2] 200 metres
• 3] 210 metres
• 4] 240 metres
• 5] 450 meters

The ratio between the speeds of two trains is 7 : 8. If the second train runs 400 km in 4 hours, then the speed of the first train is:

• 1] 70 km/hr
• 2] 75 km/hr
• 3] 84 km/hr
• 4] 87.5 km/hr

An ant moved for several seconds and covered 3 mm in the first second and 4 mm more in each successive second than its predecessor. If the ant had covered 1 mm in the first second and 8 mm more in each successive second, then the difference between the path it would cover during the same time and actual path would be more than 6 mm but less than 30 mm. find the time for which the ant moved (in seconds).

• 1] 5 s
• 2] 4 s
• 3] 6 s
• 4] 2 s
• 5] None of these

A man can row 15 km/h in still water and he finds that it takes him twice as much time to row up than as to row down the same distance in the river. The speed of current (in km/h) :

• 1] 6 km/h
• 2] 6.5 km/h
• 3] 4.5 km/h
• 4] 5 km/h

A car driver, driving in a fog, passes a pedestrian who was walking at the rate of 2 km/h in the same direction. The pedestrian could see the car for 6 minutes and it was visible to him up to distance of 0.6 km. what was speed of the car?

• 1] 30 kmph
• 2] 15 kmph
• 3] 20 kmph
• 4] 8 kmph
• 5] 12 kmph

Running at \(\frac{5}{4}\) of his usual speed, an athlete improves his timing by 5 minutes. The time he usually takes to run the same distance is:

• 1] 30 min.
• 2] 28 min.
• 3] 25 min.
• 4] 23 min.

A man goes downstream with a boat to some destination and returns upstream to his original place in 5 hours. If the speed of the boat in still water and the stream are 10 kmph and 4 kmph respectively, the distance of the destination from the starting place is:

• 1] 16 km
• 2] 18 km
• 3] 21 km
• 4] 25 km

The distance between two cities A and B is 330 km. A train starts from A at 8 am and travels towards B at 60 km/hr. Another train starts from B at 9 am and travels towards A at 75 km/hr. At what time do they meet ?

• 1] 10.00 am
• 2] 10.30 am
• 3] 11.00 am
• 4] 11.30 am

Due to the technical snag in the signal system two trains start approaching each other on the same track from two different stations, 240 km away each other. When the train starts a bird also starts moving to and fro between the two trains at 60 kmph touching each train each time. The bird initially sitting on the top of the engine of one of the trains and it moves so till these trains collide. If these trains collide one and half hour after start, then how many kilometers bird travels till the time of collision of trains?

• 1] 90 km
• 2] 130 km
• 3] 120 km
• 4] 95 km
• 5] None of these

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