Quiz Discussion

A distance of 425 km separates two trains moving towards each other at a speed of 200 km/hr each. What will be the distance between them after 1 hr 30 min, if they reduce their speed by half, every half an hour ?

• 1] 75 km
• 2] 120 km
• 3] 150 km
• 4] 200 km

A, B and C start together from the same place to walk round a circular path of length 12km. A walks at the rate of 4 km/h, B 3 km/h and C \(\frac{3}{2}\) km/h. They will meet together at the starting place at the end of:

• 1] 10 hours
• 2] 12 hours
• 3] 15 hours
• 4] 24 hours

The speed \(3\frac{1}{3}\) m/sec when expressed in km/hr becomes :

• 1] 8 km/hr
• 2] 9 km/hr
• 3] 10 km/hr
• 4] 12 km/hr

A 6 × 6 grid is cut from an 8 × 8 chessboard. In how many ways can we put two identical coins, one on the black square and one on a white square on the grid, such that they are not placed in the same row or in the same column?

• 1] 216 ways
• 2] 324 ways
• 3] 144 ways
• 4] 108 ways

A train, 110 m long is running at a speed of 60 km/hr. How many seconds does it to cross another train, 170 m long standing on parallel track ?

• 1] 15.6 seconds
• 2] 16.8 seconds
• 3] 17.2 seconds
• 4] 18 seconds

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 thief sees a jeep at a distance of 250 m, coming towards him at 36 km/h. Thief takes 5 seconds to realize that there is nothing but the police is approaching him by the jeep and start running away from police at 54 km/h. But police realise after 10 second, when the thief starts running away, that he is actually a thief and gives chase at 72 km/h. How long after thief saw police did catchup with him and what is the distance police had travel to do so?

• 1] 50 s, 1000 m
• 2] 65 s, 1150 m
• 3] 65 s, 1300 m
• 4] 45 s, 1050 m
• 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

A train travels at a speed of 30 km/hr for 12 minutes and at a speed of 45 km/hr for the next 8 minutes. The average speed of the train for this journey is :

• 1] 30 km/hr
• 2] 36 km/hr
• 3] 37.5 km/hr
• 4] 48 km/hr

The distance between two cities A and B is 330 km. A train starts from A at 8 am and travels towards B at 60 km/hr. Another train starts from B at 9 am and travels towards A at 75 km/hr. At what time do they meet ?

• 1] 10.00 am
• 2] 10.30 am
• 3] 11.00 am
• 4] 11.30 am