Quiz Discussion

Running at \(\frac{5}{4}\) of his usual speed, an athlete improves his timing by 5 minutes. The time he usually takes to run the same distance is:

• 1] 30 min.
• 2] 28 min.
• 3] 25 min.
• 4] 23 min.

Two boats, travelling at 5 km/h and 10 km/h, head directly towards each other. They begin at a distance of 20 km from each other. How far apart are they (in km) one minute before they collide?

• 1]

  \(\frac{{1}}{{12}}\)

• 2]

  \(\frac{{1}}{{6}}\)

• 3]

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

• 4]

  \(\frac{{1}}{{3}}\)

• 5]

  None of these

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

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

• 1] 10.4 km/hr
• 2] 10.8 km/hr
• 3] 11 km/hr
• 4] 12.2 km/hr

One third of a certain journey is covered at the rate of 25 km/hr, one forth at the rate of 30 km/hr and the rest at 50 km/hr. The average speed for the whole journey is :

• 1]

  35 km/hr

• 2]

  \(33\frac{1}{3}\) km/hr

• 3]

  30 km/hr

• 4]

  \(37\frac{1}{12}\) km/hr

The ratio between the speeds of two trains is 7 : 8. If the second train runs 400 km in 4 hours, then the speed of the first train is:

• 1] 70 km/hr
• 2] 75 km/hr
• 3] 84 km/hr
• 4] 87.5 km/hr

Two horses started simultaneously towards each other and meet each other 3 hr 20 mins later. How much time will it take the slower horse to cover the whole distance if the first arrived at the place of departure of the second 5 hours later than the second arrived at the point of departure of the first?

• 1] 10 hours
• 2] 5 hours
• 3] 15 hours
• 4] 6 hours
• 5] None of these

A 75 metres long train is moving at 20 kmph. It will cross a man standing on the platform in :

• 1] 12 seconds
• 2] 14 seconds
• 3] 13.5 seconds
• 4] 15.5 seconds

The speed of a motor-boat is that of the current of water as 36:5. The boat goes along with the current in 5 hours 10 minutes. It will come back in:

• 1] 5 hours 50 minutes
• 2] 6 hours
• 3] 6 hours 50 minutes
• 4] 12 hours 10 minutes

A car after traveling 18 km from a point A developed some problem in the engine and the speed became \(\frac{4}{5}\) th of its original speed. As a result, the car reached point B 45 minutes late. If the engine had developed the same problem after traveling 30 km from A, then it would have reached 36 minutes late. The original speed of the car (in km/h) is:

• 1] 25 kmph
• 2] 30 kmph
• 3] 20 kmph
• 4] 35 kmph
• 5] None of these