Quiz Discussion

A boy rides his bicycle 10 km at an average speed of 12km/hr and again travels 12km at an average speed of the 10km/hr. His average speed for the entire trip is ?

• 1]

  10.8

• 2]

  10.4

• 3]

  11

• 4]

  12

Two trains start from a certain place on two parallel tracks in the same direction. The speed of the trains are 45 km/hr and 40 km/hr respectively. The distance between the two trains after 45 minutes will be :

• 1] 2.500 km
• 2] 2.750 km
• 3] 3.750 km
• 4] 3.25 km

A boy is running at a speed of p kmph to cover a distance of 1 km. But, due to the slippery ground, his speed is reduced by q kmph (p > q). If he takes r hours to cover the distance, then:

• 1]

  \(\frac{1}{r} = p - q\)

• 2]

  r = p - q

• 3]

  \(\frac{1}{r} = p + q\)

• 4]

  r = p + r

Page and Plant are running on a track AB of length 10 metres. They start running simultaneously from the ends A and B respectively. The moment they reach either of the ends, they turn around and continue running. Page and Plant run with constant speeds of 2m/s and 5m/s respectively. How far from A (in metres) are they, when they meet for the 23rd time?

• 1]

  0 meters

• 2]

  10 meters

• 3]

  40 meters

• 4]

  \(\frac{{60}}{7}\) meters

• 5]

  None of these

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

Two guns were fired from the same place at an interval of 8 minutes. A person approaching the place observes that 5 minutes 52 seconds have elapsed between the hearing of the sound of the two guns. If the velocity of the sound is 330 m/sec, the man was approaching the place at what speed (in km/hr) ?

• 1] 24 km/hr
• 2] 27 km/hr
• 3] 30 km/hr
• 4] 36 km/hr

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 usual speed and B traveled with double his speed they would have met after 5 hours. The speed of A is :

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

A bullock cart has to cover a distance of 120 km in 15 hours. If it covers half of the journey in \(\frac{3}{5}\)th time, the second to cover the remaining distance in the time left has to be :

• 1] 6.4 km/hr
• 2] 6.67 km/hr
• 3] 10 km/hr
• 4] 15 km/hr

Two trains starting at the same time from two-stations 300 km apart and going in opposite directions, cross each other at a distance of 160 km from one of them. The ratio of their speeds is :

• 1] 7 : 9
• 2] 16 : 20
• 3] 8 : 7
• 4] 8 : 12

With an average speed of 50 km/hr, a train reaches its destination in time. If it goes with an average speed of 40 km/hr, it is late by 24 min. The total journey is :

• 1] 30 km
• 2] 40 km
• 3] 70 km
• 4] 80 km