Quiz Discussion

Ravi walks to and fro to a shopping mall. He spends 30 minutes shopping. If he walks at a speed of 10 km an hour, he returns home at 19.00 hours. If he walks at 15 km an hour, her returns home at 18.30 hours. How far must he walk in order to return home at 18.15 hours ?

• 1] 17 km/hr
• 2] 17.5 km/hr
• 3] 18 km/hr
• 4] 19 km/hr
• 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 6 cm long cigarette burns up in 15 minutes if no puff is taken.For every puff, it burns three times as fast during the duration of the puff.If the cigarette burns itself in 13 minutes, then how many puffs has the smoker taken if the average puff lasted 3 seconds?

• 1] 17
• 2] 18
• 3] 20
• 4] 22
• 5] None of these

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

Two trains 150 m and 120 m long respectively moving from opposite direction cross each other in 10 sec. If the speed of the second train is 43.2 km/hr, then the speed of the first train is :

• 1] 54 km/hr
• 2] 50 km/hr
• 3] 52 km/hr
• 4] 51 km/hr

Amit travelled black to home in a car, after visiting his friend in a distant village. When he stated at his friend's house the car had exactly 18 litres of petrol in it. He travelled along at a steady 40 kilometres per hour and managed a 10 kilometres per litre of petrol. As the car was old, the fuel tank lost fuel at the rate of half a litre per hour. Amit was lucky as his car stopped just in front of his home because it had rum out of fuel and he only just made it. How far was it from his friend's home to Amit's home ?

• 1] 150 km
• 2] 170 km
• 3] 180 km
• 4] None of these

A car covers a distance from town 1 to town 2 at the speed of 56 km/hr and from town 2 to town 1 at the speed of 53 km/hr. What is the average speed of the car ?

• 1] 53.5 km/hr
• 2] 54 km/hr
• 3] 55 km/hr
• 4] 55.5 km/hr
• 5] None of these

A boy rides his bicycle 10 km at an average speed of 12km/hr and again travels 12km at an average speed of the 10km/hr. His average speed for the entire trip is ?

• 1]

  10.8

• 2]

  10.4

• 3]

  11

• 4]

  12

The wheel of an engine of 300 cm in circumference makes 10 revolutions in 6 seconds. What is the speed of the wheel (in km/h)?

• 1] 18
• 2] 20
• 3] 27
• 4] 36

A jeep is chasing a car which is 5 km ahead. Their respective speeds are 90 km/hr and 75 km/hr. After how many minutes will the jeep catch the car ?

• 1] 10 min
• 2] 20 min
• 3] 24 min
• 4] 25 min