Quiz Discussion

A person wishes to reach his destination 90 km away 3 hours but for the first half of the journey his speed was 20 km/hr. His average speed for the rest of the journey should be :

• 1] 4 km/hr
• 2] 0.75 km/min
• 3] 1 km/min
• 4] None of these

Two trains start from P and Q respectively and travel towards each other at a speed of 50 km/hr and 40 km/hr respectively. By the time they meet the first train has travelled 100 km more than second. The distance between P and Q is:

• 1]

  500 km

• 2]

  630 km

• 3]

  660 km

• 4]

  900 km

The speeds of three cars are the ratio 2 : 3 : 4. The ratio of the taken by these cars to travel the same distance is :

• 1] 2 : 3 : 4
• 2] 4 : 3 : 2
• 3] 4 : 3 : 6
• 4] 6 : 4 : 3

From two places, 60 km apart, A and B start towards each other at the same time and meet each other after 6 hours. If A traveled with \(\frac{2}{3}\) of his speed and B traveled with double of his speed, they would have met after 5 hours. The speed of A is:

• 1] 4 km/h
• 2] 6 km/h
• 3] 10 km/h
• 4] 12 km/h

The wheel of an engine of 300 cm in circumference makes 10 revolutions in 6 seconds. What is the speed of the wheel (in km/h)?

• 1] 18
• 2] 20
• 3] 27
• 4] 36

A 75 metres long train is moving at 20 kmph. It will cross a man standing on the platform in :

• 1] 12 seconds
• 2] 14 seconds
• 3] 13.5 seconds
• 4] 15.5 seconds

A soldier fired two bullets at an interval of 335 seconds moving at a uniform speed V1. A terrorist who was running ahead of the soldier in same direction, hears the two shots at an interval of 330 seconds. If the speed of sound is 1188 km/h, then who is the faster and how much?

• 1] Soldier, 22 km/h
• 2] Terrorist, 25 km/h
• 3] Soldier, 18 km/h
• 4] Terrorist, 20 km/h
• 5] None of these

A train covers a distance of 10 km in 12 minutes. If its speed is decreased by 5 km/hr, the time taken by it to cover the same distance will be :

• 1] 10 minutes
• 2] 13 minutes 20 seconds
• 3] 13 minutes
• 4] 11 minutes 20 seconds

One of the two buses completes a journey of 300 km in 7½ hours an the other a journey of 450 km in 9 hours.  The ratio of their average speeds is:

• 1]

  2:3

• 2]

  3:4

• 3]

  4:5

• 4]

  8:9

The speed of a motor-boat is that of the current of water as 36:5. The boat goes along with the current in 5 hours 10 minutes. It will come back in:

• 1] 5 hours 50 minutes
• 2] 6 hours
• 3] 6 hours 50 minutes
• 4] 12 hours 10 minutes