Quiz Discussion

A candle of 6 cm long burns at the rate of 5 cm in 5 hour and an another candle 8 cm long burns at the rate of 6 cm in 4h. What is the time required to each candle to remain of equal lengths after burning for some hours, when they starts to burn simultaneously with uniform rate of burning?

• 1] 1 hours
• 2] 1.5 hours
• 3] 2 hours
• 4] 3 hours
• 5] 4 hours

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 coolie standing on a railway platform observe that a train going in one direction takes 4 second to pass him. Another train of same length going in opposite direction takes 5 seconds to pass him. The time taken (in seconds) by two train to cross each other will be:

• 1]

  35 seconds

• 2]

  36.5 seconds

• 3]

  \(\frac{{40}}{9}\) seconds

• 4]

  36 seconds

Each wheel of a car is making 5 revolutions per second. If the diameter of a wheel is 84 cm, then the speed of the car in cm/sec would be :

• 1] 420 cm/sec
• 2] 264 cm/sec
• 3] 1000 cm/sec
• 4] 1320 cm/sec

To reach point B from point A at 4 pm, Sara will have to travel at an average speed of 18 kmph. She will reach point B at 3 pm if she travels at an average speed of 24 kmph. At what average speed should Sara travels to reach point B at 2 pm ?

• 1] 36 km/hr
• 2] 28 km/hr
• 3] 25 km/hr
• 4] 30 km/hr

A man covers a total distance of 100 km on bicycle. For the first 2 hours, the speed was 20 km/hr and for the rest of the journey, it came down to 10 km/hr. The average speed will be :

• 1]

  \(12\frac{1}{2}\) km/hr

• 2]

  13 km/hr

• 3]

  \(\frac{1}{8}\) km/hr

• 4]

  20 km/hr

A train is 250 m long. If the train takes 50 second to cross a tree by the railway line, then the speed of the train on Km /hr is :

• 1] 9 km/hr
• 2] 5 km/hr
• 3] 18 km/hr
• 4] 10 km/hr

A person can row a boat d km upstream and the same distance downstream in 5 hours 15 minutes. Also, he can row the boat 2d km upstream in 7 hours. How long will it take to row the same distance 2d km downstream?

• 1]

  \(\frac{{3}}{{2}}\) hours

• 2]

  7 hours

• 3]

  \(\frac{{29}}{{4}}\) hours

• 4]

  \(\frac{{7}}{{2}}\) hours

A can give 40 metres start to B and 70 metres to C in a race of one kilometre how many metres starts can B give to C in a race of one kilometre ?

• 1]

  30 metres

• 2]

  \(\frac{700}{29}\) metres

• 3]

  \(31\frac{1}{4}\) metres

• 4]

  32 metres

A man travels 600 km by train at 80 km/hr, 800 km by ship at 40 km/hr, 500 km by aeroplane at 400 km/hr and 100 km by car at 50 km/hr. What is the average speed for the entire distance :

• 1]

  \({ \text{60 km/hr}}\)

• 2]

  \(60\frac{5}{123}{ \text{ km/hr}}\)

• 3]

  \({ \text{62 km/hr}}\)

• 4]

  \(65\frac{5}{123}{ \text{ km/hr}}\)