Quiz Discussion

Two guns are fired from the same place at an interval of 6 minutes. A person approaching the place observes that 5 minutes 52 seconds have elapsed between the hearings of the sound of the two guns. If the velocity of the sound is 330 m/sec, the man was approaching that place at what speed (in km/h)?

• 1] 24 kmph
• 2] 27 kmph
• 3] 30 kmph
• 4] 36 kmph

A train passes two persons walking in the same direction at a speed of 3 kmph and 5 kmph respectively in 10 seconds and 11 seconds respectively. The speed of the train is

• 1] 28 kmph
• 2] 27 kmph
• 3] 25 kmph
• 4] 24 kmph

A man crosses a road 250 metres wide in 75 seconds. His speed in km/hr is :

• 1] 10 km/hr
• 2] 12 km/hr
• 3] 12.5 km/hr
• 4] 15 km/hr

A train running at \(\frac{7}{11}\) of its own speed reached a place in 22 hours. How much time could be saved if the train would have run at its own speed?

• 1] 7 hr
• 2] 8 hr
• 3] 14 hr
• 4] 16 hr

In a race of one kilometre. A gives B a start of 100 metres and still wins by 20 seconds. But if A gives B a start of 25 seconds, B wins by 50 metres. The time taken by A to run kilometre is :

• 1]

  17 sec

• 2]

  \(\frac{{500}}{{29}}{ \text{sec}}\)

• 3]

  \(\frac{{1200}}{{29}}{ \text{sec}}\)

• 4]

  \(\frac{{700}}{{29}}{ \text{sec}}\)

A man takes 50 minutes to cover a certain distance at a speed of 6 km/hr. If he walks with a speed of 10 km/hr, he covers the same distance in :

• 1] 10 min
• 2] 20 min
• 3] 30 min
• 4] 40 min

A car traveling with \(\frac{5}{7}\) of its actual speed covers 42 km in 1 hour 40 minute 48 seconds. Find the actual speed of the car.

• 1]

  \(17\frac{6}{7}\) km/hr

• 2]

  25 km/hr

• 3]

  30 km/hr

• 4]

  35 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

In a race of 200 metres, B can give a start of 10 metres to A and C can give a start of 20 metres to B. The start that C can give to A, in the same race, is :

• 1] 30 metres
• 2] 25 metres
• 3] 29 metres
• 4] 27 metres

A and B travel the same distance at speed of 9 km/hr and 10 km/hr respectively. If A takes 36 min more than B, the distance travelled by each is :

• 1] 48 km
• 2] 54 km
• 3] 60 km
• 4] 66 km