Quiz Discussion

A train running at a speed of 54 km/hr crosses a platform in 30 seconds. The platform is renovated and its length is doubled. Now, the same train running at same speed crosses the platform in 46 seconds. Find the length of the train.

• 1] 180 metres
• 2] 200 metres
• 3] 210 metres
• 4] 240 metres
• 5] 450 meters

The distance between two places R and S is 42 km. Anita starts from R with a uniform speed of 4 km/hr towards S and at the same time Romita starts from S towards R also with some uniform speed. They meet each other after 6 hours. The speed of Romita is :

• 1] 18 km/hr
• 2] 20 km/hr
• 3] 3 km/hr
• 4] 8 km/hr

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

A is twice fast as B and B is thrice fast as C is. The journey covered by C in \(\frac{3}{2}\) hours will be covered by A is:

• 1] 15 minutes
• 2] 20 minutes
• 3] 30 minutes
• 4] 1 hour

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 man goes to a place on bicycle at speed of 16 km/hr and comes back at lower speed. If the average speed is 6.4 km/hr in total, then the return speed (in km/hr) is :

• 1] 10 km/hr
• 2] 8 km/hr
• 3] 6 km/hr
• 4] 4 km/hr

The average speed of a train in the onward journey is 25% more than that in the return journey. The train halts for one hour on reaching the destination. The total time taken for the complete to and fro journey is 17 hours, covering a distance of 800 km. The speed of the train in the onward journey is :

• 1] 45 km/hr
• 2] 47.5 km/hr
• 3] 52 km/hr
• 4] 56.25 km/hr

P and Q are 27 km away. Two trains with speed of 24 km/hr and 18 km/hr respectively start simultaneously from P and Q and travel in the same direction. They meet at a point R beyond Q. Distance QR is :

• 1] 126 km
• 2] 81 km
• 3] 48 km
• 4] 36 km

A moving train passes a platform 50 m long in 14 seconds and a lamp post in 10 seconds. The speed of the train (in km/hr) is :

• 1] 24 km/hr
• 2] 36 km/hr
• 3] 40 km/hr
• 4] 45 km/hr

Two cars are moving with speed v1, v2 towards a crossing along two roads, If their distance from the crossing be 40 metres and 50 metres at an instant of time then they do not collide if their speeds are such that :

• 1]

  v1 : v2 =16 : 25

• 2]

  v1 : v2 e 4 : 5

• 3]

  v1 : v2 e 5 : 4

• 4]

  v1 : v2 e 25 : 16