Quiz Discussion

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

The speeds of three cars are the ratio 2 : 3 : 4. The ratio of the taken by these cars to travel the same distance is :

• 1] 2 : 3 : 4
• 2] 4 : 3 : 2
• 3] 4 : 3 : 6
• 4] 6 : 4 : 3

A postman goes with a speed of 36 km/h what is the speed of postman in m/s?

• 1] 4.5 m/s
• 2] 6 m/s
• 3] 5 m/s
• 4] 10 m/s

Two planes move along a circle of circumference 1.2 kms with constant speeds. When they move in different directions, they meet every 15 seconds and when they move in the same direction one plane overtakes the other every 60 seconds. The speed of the slower plane is :

• 1] 0.02 km/sec
• 2] 0.03 km/sec
• 3] 0.04 km/sec
• 4] 0.05 km/sec

A ship, 40 kilometers from the shore, springs a leak which admits \(3\frac{3}{4}\) tonnes of water in 12 minutes. 60 tonnes would suffice to sink her, but the ship's pumps can throw out 12 tonnes of water in one hour. Find the average rate of sailing, so that she may reach the shore just as she begging to sink?

• 1]

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

• 2]

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

• 3]

  \(3\frac{1}{2}\) km/hr

• 4]

  \(4\frac{1}{2}\) km/hr

Two persons A and B started from two different places towards each other. If the ratio of their speed be 3 : 5, then what is the ratio of distance covered by A and B respectively till the point of meeting?

• 1] 1 : 2
• 2] 3 : 4
• 3] 3 : 5
• 4] 5 : 3

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

Two boats A and B start towards each other from two places, 108 km apart. Speed of the boats A and B in still water are 12 km/h and 15 km/h respectively. If A proceeds down and B up the stream, they will meet after:

• 1] 4.5 hours
• 2] 4 hours
• 3] 5.4 hours
• 4] 6 hours

The diameter of each wheel of car is 70 cm. If each wheel rotates 400 times per minutes, then the speed of the car (in km/hr) if : \(\left( {{ \text{Take }}pi = \frac{{22}}{7}} \right)\)

• 1] 5.28 km/hr
• 2] 528 km/hr
• 3] 52.8 km/hr
• 4] 0.528 km/hr

A boy is running at a speed of p kmph to cover a distance of 1 km. But, due to the slippery ground, his speed is reduced by q kmph (p > q). If he takes r hours to cover the distance, then:

• 1]

  \(\frac{1}{r} = p - q\)

• 2]

  r = p - q

• 3]

  \(\frac{1}{r} = p + q\)

• 4]

  r = p + r