Quiz Discussion

A and B start from the same point and in the same direction at 7 am to walk around a rectangular field 400 m × 300 m. A and B walk at the rate of 3 km/hr and 2.5 km/hr respectively. How many times shall they cross each other if they continue to walk till 12.30 pm ?

• 1] Not even once
• 2] Once
• 3] Twice
• 4] Thrice

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 gun is fired at a distance of 1.7 km from Ram and he hears the sound after 25 seconds. The speed of sound in meter per second is

• 1] 60 m/s
• 2] 62 m/s
• 3] 64 m/s
• 4] 68 m/s

A car covers a distance from town 1 to town 2 at the speed of 56 km/hr and from town 2 to town 1 at the speed of 53 km/hr. What is the average speed of the car ?

• 1] 53.5 km/hr
• 2] 54 km/hr
• 3] 55 km/hr
• 4] 55.5 km/hr
• 5] None of these

How long must a driver take to drive the final 70 miles of a trip if he wants to average 50 miles an hour for the entire trip and during the first part of the trip he drove 50 miles in \(1\frac{1}{2}\) hours ?

• 1] 54 min
• 2] 1 hr
• 3] 66 min
• 4] 70 min

If A travels to his school from his house at the speed of 3 km/h, then he reaches the school 5 minutes late. If he travels at the speed of 4 km/h, he reaches the school 5 minutes earlier than school time. The distance of his school from his house is:

• 1] 1 km
• 2] 2 km
• 3] 3 km
• 4] 4 km

A train travelling at 48 kmph crosses another train, having half of its length and travelling in opposite direction at 42 kmph, in 12 seconds. It also passes a railway platform in 45 seconds. The length of railway platform is:

• 1] 200m
• 2] 300m
• 3] 350m
• 4] 400m

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 man crosses a road 250 metres wide in 75 seconds. His speed in km/hr is :

• 1] 10 km/hr
• 2] 12 km/hr
• 3] 12.5 km/hr
• 4] 15 km/hr

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