Quiz Discussion

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

If a 250 m long train crosses a platform of same length as that of the train in 25 seconds, then the speed of the train is:

• 1] 150 m/sec
• 2] 200 m/sec
• 3] 20 km/h
• 4] 72 km/h

The speed of a car increases by 2 kms after every one hours. If the distance travelled in the first one hour was 35 kms, what was the total distance travelled in 12 hours ?

• 1] 456 kms
• 2] 482 kms
• 3] 552 kms
• 4] 556 kms
• 5] None of these

If a man runs at 6 kmph from his house, he misses the train at the station by 8 min. If he runs at 10 kmph, he reaches 7 min before the departure of the train. What is the distance of the station from his house? (in Km).

• 1]

  \(4\frac{3}{4}\) km

• 2]

  \(3\frac{1}{2}\) km

• 3]

  \(4\frac{1}{4}\) km

• 4]

  \(3\frac{3}{4}\) km

• 5]

  \(4\frac{1}{2}\) km

One third of a certain journey is covered at the rate of 25 km/hr, one forth at the rate of 30 km/hr and the rest at 50 km/hr. The average speed for the whole journey is :

• 1]

  35 km/hr

• 2]

  \(33\frac{1}{3}\) km/hr

• 3]

  30 km/hr

• 4]

  \(37\frac{1}{12}\) km/hr

if a man increase his speed by 3km/hr,he reaches his home in 3/4th of his normal time. if he decreases his speed by 3km/h he reaches his home 2 hours late. what is the distance the man travel to reach his home​

• 1]

  32 km

• 2]

  34 km

• 3]

  36 km

• 4]

  38 km

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

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

A passenger train 150 m long is travelling with a speed of 36 km/hr. If a man is cycling in the direction of train at 9 km/hr, the time taken by the train to pass the man is :

• 1] 10 seconds
• 2] 15 seconds
• 3] 18 seconds
• 4] 20 seconds

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