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 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 bus covered a certain distance from village A to village B at the speed of 60 km/hr. However on its return journey it got stuck in traffic and covered the same distance at the speed of 40 km/hr and took 2 hours more to reach its destination. What is the distance covered between villages A and B ?

• 1] 200 km
• 2] 240 km
• 3] 260 km
• 4] Cannot be determined
• 5] None of these

An athlete claimed that his timing for a 100 m dash should be corrected because the starting signal was gives by a gun fired from a point 10 m away from him and the timekeeper was standing close to the gun. The error due to this could be (in seconds) :

• 1] 0.03 sec
• 2] 0.1 sec
• 3] 0.5 sec
• 4] 0.7 sec

A train leaves Delhi at 4.1 pm and reaches Aligargh at 7.25 pm. The average speed of the train is 40 km/hr. What is the distance from Delhi to Aligarh ?

• 1] 120 km
• 2] 130 km
• 3] 135 km
• 4] 140 km

In covering a distance of 30 km, Abhay takes 2 hours more than Sameer. If Abhay doubles his speed, then he would take 1 hour less than Sameer. Abhay's speed is:

• 1] 5 km/hr
• 2] 6 km/hr
• 3] 6.25 km/hr
• 4] 7.5 km/hr

Two cyclists start from the same place in opposite directions. One goes towards north at 18 kmph and the other goes towards south at 20 kmph. What time will they take to be 47.5 km apart ?

• 1]

  \({ \text{1}}\frac{1}{4}{ \text{ hrs}}\)

• 2]

  \({ \text{2}}\frac{1}{4}{ \text{ hrs}}\)

• 3]

  2 hrs 23 min

• 4]

  \({ \text{2}}\frac{1}{2}{ \text{ hrs}}\)

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

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

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

A thief steals a car at 2.30 pm and drives it at 60 kmph. The theft is discovered at 3 pm and the owner sets off in another car at 75 kmph. When will he overtake the thief ?

• 1]

  4.30 pm

• 2]

  4.45 pm

• 3]

  5 pm

• 4]

   5.15 pm