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

Two trains start from the same point simultaneously and in the same direction. The first train travels at 40 km /h, and the speed of the second train is 25% more than the speed of first train. Thirty minutes later, a third train starts from same point and in the same direction. It over takes the second train 90 minutes later than it overtook the first train. What is the speed of the third train?

• 1] 20 km/h
• 2] 40 km/h
• 3] 60 km/h
• 4] 50 km/h
• 5] 80 km/h

A train can travel 50% faster than a car. Both start from point A at the same time and reach point B 75 kms away from A at the same time. On the way, however, the train lost about 12.5 minutes while stopping at the stations. The speed of the car is :

• 1] 100 kmph
• 2] 110 kmph
• 3] 120 kmph
• 4] 130 kmph

The ratio between the speed of a bus and train is 15 : 27 respectively. Also, a car covered a distance of 720 km in 9 hours. The speed of the Bus is three-fourth the speed of the car. How much distance will the train cover in 7 hours?

• 1] 760 km
• 2] 756 km
• 3] 740 km
• 4] None of these

A train met with an accident 120 km from station A. It completed the remaining journey at \(\frac{5}{6}\) of its previous speed and reached 2 hours late at station B. Had the accident taken place 300 km further, it would have been only 1 hour late. What is the speed of the train?

• 1] 100 km/h
• 2] 12 km/h
• 3] 60 km/h
• 4] 50 km/h

A boat covers 48 km upstream and 72 km downstream in 12 hours, while it covers 72 km upstream and 48 km downstream in 13 hours The speed of stream is :

• 1] 2 kmph
• 2] 2.2 kmph
• 3] 2.5 kmph
• 4] 4 kmph

A man on tour travels first 160 km at 64 km/hr and the next 160 km at 80 km/hr. The average speed for the first 320 km of the tour is:

• 1] 35.55 km/hr
• 2] 36 km/hr
• 3] 71.11 km/hr
• 4] 71 km/hr

A train covers a distance of 10 km in 12 minutes. If its speed is decreased by 5 km/hr, the time taken by it to cover the same distance will be :

• 1] 10 minutes
• 2] 13 minutes 20 seconds
• 3] 13 minutes
• 4] 11 minutes 20 seconds

Two boys A and B start at the same time to ride from Delhi to Meerut, 60 km away. A travels 4 km an hours slower than B, B reaches Meerut and at once turns back meeting A, 12 km from Meerut. A's rate was :

• 1] 4 km/hr
• 2] 8 km/hr
• 3] 12 km/hr
• 4] 16 km/hr

A man completes a certain journey by a car. If he covered 30% of the distance at the speed of 20kmph. 60% of the distance at 40km/h and the remaining of the distance at 10 kmph, his average speed is:

• 1] 25 km/h
• 2] 28 km/h
• 3] 30 km/h
• 4] 33 km/h