Quiz Discussion

A man can row 15 km/h in still water and he finds that it takes him twice as much time to row up than as to row down the same distance in the river. The speed of current (in km/h) :

• 1] 6 km/h
• 2] 6.5 km/h
• 3] 4.5 km/h
• 4] 5 km/h

The wheel of an engine of 300 cm in circumference makes 10 revolutions in 6 seconds. What is the speed of the wheel (in km/h)?

• 1] 18
• 2] 20
• 3] 27
• 4] 36

With an uniform speed, a car covers a distance in 8 hours. had the speed been increased by 4 km/hr, the same distance could have been covered in 7 hr and 30 min. What is the distance covered ?

• 1] 420 km
• 2] 480 km
• 3] 520 km
• 4] 640 km

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

Four people are running around a circular ground from a point on the circumference at 9.00 am. For one round, these four persons take respectively 40, 50, 60 and 30 minutes. At what time will they meet together again ?

• 1] 4.30 pm
• 2] 7.00 pm
• 3] 6.00 pm
• 4] 5.30 pm

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 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

There are 8 equidistant points A, B, C, D, E, F, G and H in the clockwise direction on the periphery of a circle. In a time interval t, a person reaches from A to C with uniform motion while another person reaches the point E from the point B during the same time interval with uniform motion. Both the persons move in the same direction along the circumference of the circle and start at the same instant. How much time after the start, will the two persons meet each other ?

• 1] 4t
• 2] 7t
• 3] 9t
• 4] Never

The average speed of a train in the onward journey is 25% more than that in the return journey. The train halts for one hour on reaching the destination. The total time taken for the complete to and fro journey is 17 hours, covering a distance of 800 km. The speed of the train in the onward journey is :

• 1] 45 km/hr
• 2] 47.5 km/hr
• 3] 52 km/hr
• 4] 56.25 km/hr

Two ports A and B are 300 km apart. Two ships leave A for B such that the second leaves 8 hours after the first. The ships arrive at B simultaneously. Find the time the slower ship spent on the trip if the speed of one of them is 10 km/h higher than that of the other.

• 1] 25 hours
• 2] 20 hours
• 3] 15 hours
• 4] 20 hours
• 5] 24 hours