Quiz Discussion

A boy is running at a speed of p kmph to cover a distance of 1 km. But, due to the slippery ground, his speed is reduced by q kmph (p > q). If he takes r hours to cover the distance, then:

• 1]

  \(\frac{1}{r} = p - q\)

• 2]

  r = p - q

• 3]

  \(\frac{1}{r} = p + q\)

• 4]

  r = p + r

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

A car takes 15 minutes less to cover a distance of 75 km, if it increases its speed by 10 km/hr from its usual speed. How much time would it take to cover a distance of 300 km using this speed ?

• 1]

  5 hrs

• 2]

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

• 3]

  6 hrs

• 4]

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

A plane flying north at 500 mph passes over a city at 12 noon. A plane flying east at the same altitude passes over the same city at 12.30 pm. The plane is flying east at 400 mph. To the nearest hundred miles, how far apart are the two planes at 2 pm ?

• 1] 600 miles
• 2] 1000 miles
• 3] 1100 miles
• 4] 1200 miles
• 5] 1300 miles

A train passes two persons walking in the same direction at a speed of 3 kmph and 5 kmph respectively in 10 seconds and 11 seconds respectively. The speed of the train is

• 1] 28 kmph
• 2] 27 kmph
• 3] 25 kmph
• 4] 24 kmph

Walking \({\frac{6}{7}}\) th of his usual speed, a man is 12 minutes too late. The usual time taken by him to cover that distance is :

• 1] 1 hour
• 2] 1 hr 12 min
• 3] 1 hr 15 min
• 4] 1 hr 20 min

A moving train crosses a man standing on a platform and the platform 300 metres long in 10 seconds and 25 seconds respectively. What will be the time taken by the train to cross a platform 200 metre long ?

• 1]

  \(16\frac{2}{3} \)seconds

• 2]

  18 seconds

• 3]

  20 seconds

• 4]

  22 seconds

Two planes move along a circle of circumference 1.2 km with constant speeds. When they move in different directions, they meet every 15 seconds and when they move in the same direction, one plane overtakes the other every 60 seconds. Find the speed of the slower plane.

• 1] 0.04 km/s
• 2] 0.03 km/s
• 3] 0.05 km/s
• 4] 0.02 km/s
• 5] None of these

The area of square park is 25 sq. Km. Time taken to complete a round of the field once, at a speed of 3 kmph is:

• 1] 4 hours 60 minutes
• 2] 4 hours 50 minutes
• 3] 6 hours 40 minutes
• 4] 5 hours 40 minutes

Two trains start from a certain place on two parallel tracks in the same direction. The speed of the trains are 45 km/hr and 40 km/hr respectively. The distance between the two trains after 45 minutes will be :

• 1] 2.500 km
• 2] 2.750 km
• 3] 3.750 km
• 4] 3.25 km