Quiz Discussion

An individual is cycling at a speed of 25 km per hour. He catches his predecessor who had started earlier in two hours. What is the speed of his predecessor who had started 3 hours earlier ?

• 1] 15 kmph
• 2] 12 kmph
• 3] 10 kmph
• 4] 8 kmph

How long must a driver take to drive the final 70 miles of a trip if he wants to average 50 miles an hour for the entire trip and during the first part of the trip he drove 50 miles in \(1\frac{1}{2}\) hours ?

• 1] 54 min
• 2] 1 hr
• 3] 66 min
• 4] 70 min

A man goes to the fair with his son and dog. Unfortunately man misses his son which he realizes 20 minutes later. The son comes back towards his home at the speed of 20 m/min and man follows him at 40 m/min. The dog runs to son and comes back to the man to show him the direction of his son. He keeps moving to and fro at 60 m/min between son and father, till the man meets the son. What is the distance traveled by the dog in the direction of the son?

• 1] 800 m
• 2] 1675 m
• 3] 848 m
• 4] 1000 m
• 5] None of these

A train passes two bridges of length 500 metres and 250 metres in 100 seconds and 60 seconds respectively. The length of the train is :

• 1] 125 metres
• 2] 250 metres
• 3] 120 metres
• 4] 152 metres

A man travels 600 km by train at 80 km/hr, 800 km by ship at 40 km/hr, 500 km by aeroplane at 400 km/hr and 100 km by car at 50 km/hr. What is the average speed for the entire distance :

• 1]

  \({ \text{60 km/hr}}\)

• 2]

  \(60\frac{5}{123}{ \text{ km/hr}}\)

• 3]

  \({ \text{62 km/hr}}\)

• 4]

  \(65\frac{5}{123}{ \text{ km/hr}}\)

Two persons A and B start simultaneously from P and Q respectively. A meets B at a distance of 60m from P. After A reaches Q and B reaches P, they turn around and start walking in opposite direction, now B meets A at a distance of 40m from Q. Find distance between P and Q?

• 1] 160 m
• 2] 100 m
• 3] 140 m
• 4] 105 m
• 5] None of These

A star is 8.1 × 1013 km away from the earth. Suppose light travels at the speed of 3.0 × 105 km per second. How long will it take the light from the star to reach the earth ?

• 1] 7.5 × 103 hours
• 2] 7.5 × 104 hours
• 3] 2.7 × 1010 seconds
• 4] 2.7 × 1011 seconds

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:

• 1] 35.55 km/hr
• 2] 36 km/hr
• 3] 71.11 km/hr
• 4] 71 km/hr

The speed of 90 km per hour is same as :

• 1] 9 m/s
• 2] 20 m/s
• 3] 25 m/s
• 4] 28 m/s

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