Quiz Discussion

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

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 train without stopping travels 60 km/h and with stoppage 40 km/h. What is the time taken for stoppage on a route 300 km?

• 1] 10 hours
• 2] 20 hours
• 3] 5 hours
• 4] 2.5 hours

Two planes move along a circle of circumference 1.2 km with constant speeds. When they move in different directions, they meet every 15 seconds and when they move in the same direction, one plane overtakes the other every 60 seconds. Find the speed of the slower plane.

• 1] 0.04 km/s
• 2] 0.03 km/s
• 3] 0.05 km/s
• 4] 0.02 km/s
• 5] None of these

A man reduces his speed from 20 kmph to 18 kmph. So, he takes 10 minutes more than the normal time. what is the distance traveled by him.

• 1] 30 km
• 2] 25 km
• 3] 50 km
• 4] 36 km

An aeroplane covers a certain distance at a speed of 240 kmph in 5 hours. To cover the same distance in \(1\frac{2}{3}\) hours, it must travel at a speed of :

• 1] 300 kmph
• 2] 360 kmph
• 3] 600 kmph
• 4] 720 kmph

Sabarmati express takes 18 seconds to pass completely through a station 162 m long and 15 seconds through another station 120 m long. The length of the train is :

• 1] 132 m
• 2] 100 m
• 3] 80 m
• 4] 90 m

A plan left 40 minutes late due to bad whether and order to reach its destination 1600 km away in time, it had increase its speed by 400 kmph from its usual speed. Find the usual speed of the plane?

• 1] 600 km/hour
• 2] 400 km/hour
• 3] 1000 km/hour
• 4] 800 km/hour

A dog after traveling 50 km meets a swami who counsels him to go slower. He then proceeds at \(\frac{3}{4} \)of his former speed and arrives at his destination 35 min late. Had the meeting occurred 24 km further the dog would have reached its destination 25 min late. The speed of the dog is:

• 1] 48 kmph
• 2] 36 kmph
• 3] 54 kmph
• 4] 58 kmph

An aeroplane flies from place A to place B at the speed of 500 km/hr. On the return journey, its speed is 700 km/hr. The average speed of the aeroplane for the entire journey is ?

• 1]

  \(566\frac{2}{3}{ \text{ km/hr}}\)

• 2]

  \(583\frac{1}{3}{ \text{ km/hr}}\)

• 3]

  \(583\frac{2}{3}{ \text{ km/hr}}\)

• 4]

  \(600{ \text{ km/hr}}\)