Quiz Discussion

A man goes downstream with a boat to some destination and returns upstream to his original place in 5 hours. If the speed of the boat in still water and the stream are 10 kmph and 4 kmph respectively, the distance of the destination from the starting place is:

• 1] 16 km
• 2] 18 km
• 3] 21 km
• 4] 25 km

A runs twice as fast as B and B runs thrice as fast as C. The distance covered by C in 72 minutes, will be covered by A in:

• 1] 18 minutes
• 2] 24 minutes
• 3] 16 minutes
• 4] 12 minutes

A thief running at 8 km/hr is chased by a policeman whose speed is 10 km/hr. If the thief is 100 metres ahead of the policeman, then the time required for the policeman to catch the thief will be :

• 1] 2 minutes
• 2] 3 minutes
• 3] 6 minutes
• 4] 10 minutes

A person wishes to reach his destination 90 km away 3 hours but for the first half of the journey his speed was 20 km/hr. His average speed for the rest of the journey should be :

• 1] 4 km/hr
• 2] 0.75 km/min
• 3] 1 km/min
• 4] None of these

A monkey climbs a 60 m high pole. In first minute he climbs 6 m and slips down 3 m in the next minute. How much time is required by it to reach the top?

• 1] 35 minutes
• 2] 33 minutes
• 3] 37 minutes
• 4] 40 minutes

Two trains 105 meters and 90 meters long, run at the speeds of 45 kmph and 72 kmph respectively, in opposite directions on parallel tracks. The time which they take to cross each other, is:

• 1] 8 seconds
• 2] 6 seconds
• 3] 7 seconds
• 4] 5 seconds

Two cars start simultaneously from cities A and B, towards B and A respectively, on the same route. Once the two cars reach their destinations they turned around and move towards the other city without any loss of time. The two cars continue shuttling in this manner for exactly 20 hours. If the speed of the car starting from A is 60km/hr and the speed of the car starting from B is 40km/hr and the distance between the two cities is 120 km, find the number of times the two cars cross each other?

• 1] 8
• 2] 10
• 3] 12
• 4] 20
• 5] Can't be determined

The speed of electric train is 25% more than that of steam engine train. What is the time taken by an electric train to cover a distance which a steam engine takes 4 hours 25 minutes to cover ?

• 1]

  \(3\frac{1}{10}\) hrs

• 2]

  \(3\frac{11}{15}\) hrs

• 3]

  \(3\frac{11}{12}\) hrs

• 4]

  \(3\frac{8}{15}\) hrs

A person travels three equal distance at a speed of x km/hr, y km/hr and z km/hr respectively. What is the average speed for the whole journey ?

• 1]

  \(\frac{{xyz}}{{3\left( {xy + yz + zx} \right)}}\)    km/hr

• 2]

  \(\frac{{xyz}}{{\left( {xy + yz + zx} \right)}}\)    km/hr

• 3]

  \(\frac{{\left( {xy + yz + zx} \right)}}{{xyz}}\)    km/hr

• 4]

  \(\frac{{3xyz}}{{\left( {xy + yz + zx} \right)}}\)    km/hr

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