Quiz Discussion

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

A certain distance is covered at a certain speed. If half of this distance is covered in double the time, the ratio of the two speed is :

• 1] 1 : 16
• 2] 4 : 1
• 3] 2 : 1
• 4] 1 : 4

An aeroplane flies twice as fast as a train which covers 60 miles in 80 minutes. What distance will the aeroplane cover in 20 minutes ?

• 1] 30 miles
• 2] 35 miles
• 3] 40 miles
• 4] 50 miles

Two cyclists start from the same place in opposite directions. One goes towards north at 18 kmph and the other goes towards south at 20 kmph. What time will they take to be 47.5 km apart ?

• 1]

  \({ \text{1}}\frac{1}{4}{ \text{ hrs}}\)

• 2]

  \({ \text{2}}\frac{1}{4}{ \text{ hrs}}\)

• 3]

  2 hrs 23 min

• 4]

  \({ \text{2}}\frac{1}{2}{ \text{ hrs}}\)

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 plane left half an hour later than the scheduled time and in order to reach its destination 1500 kilometers away in time, it had to increase its speed by 33.33 percent over its usual speed. Find its increased speed.

• 1] 250 kmph
• 2] 500 kmph
• 3] 750 kmph
• 4] 1000 kmph
• 5] 1200 kmph

A salesman travels a distance of 50 km in 2 hours and 30 minutes. How much faster, in kilometres per hour, n a n average must he travel to make such a trip in 5656 hour less time?

• 1]

  10

• 2]

  20

• 3]

  30

• 4]

  None Of these

Two cars start simultaneously from cities A and B, towards B and A respectively, on the same route. Once the two cars reach their destinations they turned around and move towards the other city without any loss of time. The two cars continue shuttling in this manner for exactly 20 hours. If the speed of the car starting from A is 60km/hr and the speed of the car starting from B is 40km/hr and the distance between the two cities is 120 km, find the number of times the two cars cross each other?

• 1] 8
• 2] 10
• 3] 12
• 4] 20
• 5] Can't be determined

A train travels at a speed of 30 km/hr for 12 minutes and at a speed of 45 km/hr for the next 8 minutes. The average speed of the train for this journey is :

• 1] 30 km/hr
• 2] 36 km/hr
• 3] 37.5 km/hr
• 4] 48 km/hr

Two trains 150 m and 120 m long respectively moving from opposite direction cross each other in 10 sec. If the speed of the second train is 43.2 km/hr, then the speed of the first train is :

• 1] 54 km/hr
• 2] 50 km/hr
• 3] 52 km/hr
• 4] 51 km/hr