Quiz Discussion

A student goes to school at the rate of \(2\frac{1}{2}\) km/hr and reaches 6 min late. If he travels at the speed of 3 km/hr he is 10 min early. What is the distance to the school?

• 1]

  4 km

• 2]

  \(3\frac{1}{4}\) km

• 3]

  1 km

• 4]

  \(3\frac{1}{2}\) km

A train 300 m long is running with a speed of 54 km/hr. In what time it cross a telephone pole ?

• 1] 20 seconds
• 2] 15 seconds
• 3] 17 seconds
• 4] 18 seconds

If a person walks at 14 km/hr instead of 10 km/hr, he would have walked 20 km more. The actual distance travelled by him is:

• 1] 50 km
• 2] 56 km
• 3] 70 km
• 4] 80 km

A man walking at the rate of 5 km/hr crosses a bridge in 15 min. The length of the bridge (in metres) is :

• 1] 600 metres
• 2] 750 metres
• 3] 1000 metres
• 4] 1250 metres

A train covers a distance of 10 km in 12 minutes. If its speed is decreased by 5 km/hr, the time taken by it to cover the same distance will be :

• 1]

  10 minutes

• 2]

  13 minutes 20 seconds

• 3]

  13 minutes

• 4]

  11 minutes 20 seconds

A man can walk uphill at the rate of \(2\frac{1}{2}\) km/hr and downhill at the rate of \(3\frac{1}{4}\) km/hr. If the total time required to walk a certain distance up the hill and return to the starting point was 4 hr 36 min, then what was the distance walked up the hill by the man ?

• 1]

  4 km

• 2]

  \(4\frac{1}{2} \)km

• 3]

  \(5\frac{1}{2}\) km

• 4]

  \(6\frac{1}{2}\)km

Three runners A, B and C run a race, with runner A finishing 12 metres ahead of runner B and 18 metres ahead of runner C, in another race of same type runner B finished 8 metres ahead of runner C. Each runner travels the entire distance at a constant speed. The length of the race is :

• 1] 36 metres
• 2] 48 metres
• 3] 60 metres
• 4] 72 metres

A train increases its normal speed by 12.5% and reaches its destination 20 min earlier. What is the actual time taken by the train in the journey ?

• 1] 145 minutes
• 2] 160 minutes
• 3] 180 minutes
• 4] 220 minutes

A plane left half an hour later than the scheduled time and in order to reach its destination 1500 kilometers away in time, it had to increase its speed by 33.33 percent over its usual speed. Find its increased speed.

• 1] 250 kmph
• 2] 500 kmph
• 3] 750 kmph
• 4] 1000 kmph
• 5] 1200 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