Quiz Discussion

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

Train X leaves New York at 1 am and travels east at a constant speed of x mph. If train Z leaves New York at 2 am and travels east, at what constant rate of speed will train Z have to travel in order to catch train X at exactly 5.30 am ?

• 1]

  \(\frac{5}{6}x\)

• 2]

  \(\frac{9}{8}x\)

• 3]

  \(\frac{6}{5}x\)

• 4]

  \(\frac{9}{7}x\)

• 5]

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

A man on tour travels 160 km by car at 64 km/hr and another 160 km by bus at 80 km/hr. The average speed for the whole journey is :

• 1] 35.55 km/hr
• 2] 36 km/hr
• 3] 71.11 km/hr
• 4] 71 km/hr

Two trains starting at the same time from two-stations 300 km apart and going in opposite directions, cross each other at a distance of 160 km from one of them. The ratio of their speeds is :

• 1] 7 : 9
• 2] 16 : 20
• 3] 8 : 7
• 4] 8 : 12

In a race of 1000m, A can beat B by 100m. In a 400m, B beats C by 40m. In a race of 500m. A will beat C by

• 1] 95m
• 2] 50m
• 3] 45m
• 4] 60m

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 man goes to the fair with his son and dog. Unfortunately man misses his son which he realizes 20 minutes later. The son comes back towards his home at the speed of 20 m/min and man follows him at 40 m/min. The dog runs to son and comes back to the man to show him the direction of his son. He keeps moving to and fro at 60 m/min between son and father, till the man meets the son. What is the distance traveled by the dog in the direction of the son?

• 1] 800 m
• 2] 1675 m
• 3] 848 m
• 4] 1000 m
• 5] None of these

A car traveling with \(\frac{5}{7}\) of its actual speed covers 42 km in 1 hour 40 minute 48 seconds. Find the actual speed of the car.

• 1]

  \(17\frac{6}{7}\) km/hr

• 2]

  25 km/hr

• 3]

  30 km/hr

• 4]

  35 km/hr

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

A thief seeing a policeman at a distance of 150 metres starts running at 10 kmph and the policeman gives immediate chase at 12 kmph. When the thief is overtaken the thief has traveled a distance of:

• 1] 750 m
• 2] 900 m
• 3] 800 m
• 4] 1 km