Quiz Discussion

Two boats, travelling at 5 km/h and 10 km/h, head directly towards each other. They begin at a distance of 20 km from each other. How far apart are they (in km) one minute before they collide?

• 1]

  \(\frac{{1}}{{12}}\)

• 2]

  \(\frac{{1}}{{6}}\)

• 3]

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

• 4]

  \(\frac{{1}}{{3}}\)

• 5]

  None of these

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

Two cyclists start on a circular track from a given point but in opposite directions with speeds of 7 m/sec and 8 m/sec respectively. If the circumference of the circle is 300 metres, after what time will they meet at the starting point ?

• 1] 20 sec
• 2] 100 sec
• 3] 200 sec
• 4] 300 sec

The ratio of speeds of A and B is 2 : 3 and therefore A takes 20 minutes more time than B. What is the ratio of time taken by A and B?

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

A man walks a certain distance in certain time, if he had gone 3 km per hour faster, he would have taken 1 hour less than the scheduled time. If he had gone 2 km per hour slower, he would have taken one hour longer on the road. The distance (in km) is :

• 1] 60
• 2] 45
• 3] 65
• 4] 80

A train passes two bridges of length 800 m and 400 m in 100 seconds and 60 seconds respectively. The length of the train is:

• 1] 80m
• 2] 90m
• 3] 200m
• 4] 150m

A thief steals a car at 2.30 pm and drives it at 60 kmph. The theft is discovered at 3 pm and the owner sets off in another car at 75 kmph. When will he overtake the thief ?

• 1]

  4.30 pm

• 2]

  4.45 pm

• 3]

  5 pm

• 4]

   5.15 pm

P and Q are 27 km away. Two trains with speed of 24 km/hr and 18 km/hr respectively start simultaneously from P and Q and travel in the same direction. They meet at a point R beyond Q. Distance QR is :

• 1] 126 km
• 2] 81 km
• 3] 48 km
• 4] 36 km

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

The speed of A and B are in the ratio 3 : 4. A takes 20 minutes more than B to reach a destination. Time in which A reach the destination?

• 1]

  \(1\frac{1}{3}\) hours

• 2]

  2 hours

• 3]

  \(2\frac{2}{3}\) hours

• 4]

  \(1\frac{2}{3}\) hours