Quiz Discussion

An aeroplane flies from place A to place B at the speed of 500 km/hr. On the return journey, its speed is 700 km/hr. The average speed of the aeroplane for the entire journey is ?

• 1]

  \(566\frac{2}{3}{ \text{ km/hr}}\)

• 2]

  \(583\frac{1}{3}{ \text{ km/hr}}\)

• 3]

  \(583\frac{2}{3}{ \text{ km/hr}}\)

• 4]

  \(600{ \text{ km/hr}}\)

A person can row \(7\frac{1}{2}\) km an hour in still water. Finds that it takes twice the time to row upstream than the time to row downstream. The speed of the stream is:

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

One of the two buses completes a journey of 300 km in 7½ hours an the other a journey of 450 km in 9 hours.  The ratio of their average speeds is:

• 1]

  2:3

• 2]

  3:4

• 3]

  4:5

• 4]

  8:9

Points 'A' and 'B' are 70 km apart on a highway and two cars start at the same time. If they travel in the same direction, they meet in 7 hours, but if they travel towards each other they meet in one hour. Find the speed of the two cars (in km/hr).

• 1] 20, 30
• 2] 40, 30
• 3] 30, 50
• 4] 20, 40

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

A train passes two persons walking in the same direction at a speed of 3 kmph and 5 kmph respectively in 10 seconds and 11 seconds respectively. The speed of the train is

• 1] 28 kmph
• 2] 27 kmph
• 3] 25 kmph
• 4] 24 kmph

A train covers a distance between two stations A and B in 45 minutes. If the speed of the train is reduced by 5 km/hr, then it covers the distance in 48 minutes. The distance between the stations A and B is :

• 1] 55 km
• 2] 60 km
• 3] 64 km
• 4] 80 km

A 6 × 6 grid is cut from an 8 × 8 chessboard. In how many ways can we put two identical coins, one on the black square and one on a white square on the grid, such that they are not placed in the same row or in the same column?

• 1] 216 ways
• 2] 324 ways
• 3] 144 ways
• 4] 108 ways

If a 250 m long train crosses a platform of same length as that of the train in 25 seconds, then the speed of the train is:

• 1] 150 m/sec
• 2] 200 m/sec
• 3] 20 km/h
• 4] 72 km/h

A square playground measure 1127.6164 sq.m. If a man walks \(2\frac{9}{{20}}\) m a minute, the time taken by him to walk one round around it is approximately :

• 1] 50.82 minutes
• 2] 54.82 minutes
• 3] 54.62 minutes
• 4] 50.62 minutes