Quiz Discussion

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 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

A man reduces his speed from 20 kmph to 18 kmph. So, he takes 10 minutes more than the normal time. what is the distance traveled by him.

• 1] 30 km
• 2] 25 km
• 3] 50 km
• 4] 36 km

A and B start at the same time with speed of 40 km/hr. and 50 km/hr respectively. If in covering the journey A takes 15 min longer than B, the total distance of the journey is :

• 1] 40 km
• 2] 48 km
• 3] 50 km
• 4] 52 km

The speed of A and B are in the ratio 3 : 4. A takes 20 minutes more than B to reach a destination. Time in which A reach the destination?

• 1]

  \(1\frac{1}{3}\) hours

• 2]

  2 hours

• 3]

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

• 4]

  \(1\frac{2}{3}\) hours

An express train travelled at an average speed of 100 km/hr, stopping for 3 minutes after every 75 km. How much time does the Train take to travel between two places which are 600 km apart?

• 1]

  6 hrs 21 min

• 2]

  6 hrs 24 min

• 3]

  6 hrs 27 min

• 4]

  6 hrs 30 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 railway passenger counts the telegraph poles on the rail road as he passes them. The telegraph poles are at a distance of 50 metres. What will be his count in 4 hours, if the speed of the train is 45 km per hour.

• 1] 600
• 2] 2500
• 3] 3600
• 4] 5000

An ant moved for several seconds and covered 3 mm in the first second and 4 mm more in each successive second than its predecessor. If the ant had covered 1 mm in the first second and 8 mm more in each successive second, then the difference between the path it would cover during the same time and actual path would be more than 6 mm but less than 30 mm. find the time for which the ant moved (in seconds).

• 1] 5 s
• 2] 4 s
• 3] 6 s
• 4] 2 s
• 5] None of these

A train running at \(\frac{7}{11}\) of its own speed reached a place in 22 hours. How much time could be saved if the train would have run at its own speed?

• 1] 7 hr
• 2] 8 hr
• 3] 14 hr
• 4] 16 hr