Quiz Discussion

A person travels from P to Q at a speed of 40 kmph and returns by increasing his speed by 50%. What is his average speed for both the trips ?

• 1] 36 kmph
• 2] 45 kmph
• 3] 48 kmph
• 4] 50 kmph

A is twice fast as B and B is thrice fast as C. The journey covered by C in 78 minutes will be covered by A in :

• 1] 13 min
• 2] 15.5 min
• 3] 17 min
• 4] 12 min

A man goes to the fair with his son and dog. Unfortunately man misses his son which he realizes 20 minutes later. The son comes back towards his home at the speed of 20 m/min and man follows him at 40 m/min. The dog runs to son and comes back to the man to show him the direction of his son. He keeps moving to and fro at 60 m/min between son and father, till the man meets the son. What is the distance traveled by the dog in the direction of the son?

• 1] 800 m
• 2] 1675 m
• 3] 848 m
• 4] 1000 m
• 5] None of these

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

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

Two rifles are fired from the same place at a difference of 11 minutes 45 seconds. But a man who is coming towards the place in a train hears the second sound after 11 minutes. Find the speed of train. (speed of sound = 330 m/s)

• 1] 72 kmph
• 2] 36 kmph
• 3] 81 kmph
• 4] 108 kmph
• 5] None of these

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

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

Paschim Express left Delhi for Mumbai at 14.30 hrs travelling at a speed of 60 kmph and August Kranti Express left Delhi for Mumbai in the same day at 16.30 hrs travelling at a speed of 80 kmph. How far away from Delhi will the two trains meet (excluding stoppages) ?

• 1] 120 km
• 2] 360 km
• 3] 480 km
• 4] 500 km

Karan and Arjun run a 100 metre race, where Karan beats Arjun by 10 metre. To do a favour to Arjun, Karan starts 10 metre behind the starting line in a second 100 race. They both run at their earlier speeds. Which of the following is true in connection with the race?

• 1] Karan and Arjun reach the finishing line simultaneously
• 2] Arjun beats Karan by 1 metre
• 3] Arjun beats Karan by 11 metre
• 4] Karan beats Arjun by 1 metre
• 5] Cannot be said