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

In a race of 200 meters, B can gives a start of 10 meters to A, and C can gives a start of 20 meters to B. The starts that C can gives to A, in the same race is:

• 1] 30 meters
• 2] 25 meters
• 3] 29 meters
• 4] 27 meters

A car travels at a speed of 60 km/hr and covers a particular distance in one hour. How long will it take for another car to cover the same distance at 40 km/hr ?

• 1]

  \(\frac{5}{2}\) hours

• 2]

  2 hours

• 3]

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

• 4]

  1 hour

A train travelling with a speed of 60 kmph catches another train travelling in the same direction and then leaves it 120 m behind in 18 seconds. The speed of the second train is

• 1] 26 kmph
• 2] 35 kmph
• 3] 36 kmph
• 4] 63 kmph

Two guns are fired from the same place at an interval of 6 minutes. A person approaching the place observes that 5 minutes 52 seconds have elapsed between the hearings of the sound of the two guns. If the velocity of the sound is 330 m/sec, the man was approaching that place at what speed (in km/h)?

• 1] 24 kmph
• 2] 27 kmph
• 3] 30 kmph
• 4] 36 kmph

A bus covers three successive 3 km stretches at speed of 10 km/hr, 20 km/hr and 60 km/hr respectively. Its average speed over this distance is :

• 1] 30 km/hr
• 2] 25 km/hr
• 3] 18 km/hr
• 4] 10 km/hr

A and B start from the same point and in the same direction at 7 am to walk around a rectangular field 400 m × 300 m. A and B walk at the rate of 3 km/hr and 2.5 km/hr respectively. How many times shall they cross each other if they continue to walk till 12.30 pm ?

• 1] Not even once
• 2] Once
• 3] Twice
• 4] Thrice

Two trains start from the same point simultaneously and in the same direction. The first train travels at 40 km /h, and the speed of the second train is 25% more than the speed of first train. Thirty minutes later, a third train starts from same point and in the same direction. It over takes the second train 90 minutes later than it overtook the first train. What is the speed of the third train?

• 1] 20 km/h
• 2] 40 km/h
• 3] 60 km/h
• 4] 50 km/h
• 5] 80 km/h

A walk at a uniform rate of 4 km an hour; and 4 hr after his start, B bicycles after him at the uniform rate of 10 km an hour. How far from the starting point will B catch A ?

• 1] 16.7 km
• 2] 18.6 km
• 3] 21.5 km
• 4] 26.7 km

A train 350 m long is running at the speed of 36 km/h. If it crosses a tunnel in 1 minute, the length of the tunnel in metres:

• 1] 200 meters
• 2] 250 meters
• 3] 300 meters
• 4] 150 meters