Quiz Discussion

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

Ashok left from place A for place B at 8 am and Rahul left place B for place A at 10.00 am the distance between place A and B is 637 km. If Ashok and Rahul are travelling at a uniform speed of 39 kmph and 47 kmph respectively, at what time will they meet ?

• 1] 5.30 pm
• 2] 4.30 pm
• 3] 5 pm
• 4] 4 pm

A man covered a certain distance at some speed. Had he moved 3 kmph faster, he would have taken 40 minutes less. If he had moved 2 kmph slower, he would have taken 40 minutes more. The distance (in km) is :

• 1]

  35 km

• 2]

  \(36\frac{2}{3}\) km

• 3]

  \(37\frac{1}{2}\) km

• 4]

  40 km

A car travels from P to Q at a constant speed. If its speed were increased by 10 km/hr, it would have taken one hour lesser to cover the distance. It would have taken further 45 minutes lesser if the speed was further increased by 10 km/hr. The distance between two cities is :

• 1] 540 km
• 2] 420 km
• 3] 600 km
• 4] 620 km

A 6 × 6 grid is cut from an 8 × 8 chessboard. In how many ways can we put two identical coins, one on the black square and one on a white square on the grid, such that they are not placed in the same row or in the same column?

• 1] 216 ways
• 2] 324 ways
• 3] 144 ways
• 4] 108 ways

The wheel of an engine of 300 cm in circumference makes 10 revolutions in 6 seconds. What is the speed of the wheel (in km/h)?

• 1] 18
• 2] 20
• 3] 27
• 4] 36

A runs twice as fast as B and B runs thrice as fast as C. The distance covered by C in 72 minutes, will be covered by A in:

• 1] 18 minutes
• 2] 24 minutes
• 3] 16 minutes
• 4] 12 minutes

A square playground measure 1127.6164 sq.m. If a man walks \(2\frac{9}{{20}}\) m a minute, the time taken by him to walk one round around it is approximately :

• 1] 50.82 minutes
• 2] 54.82 minutes
• 3] 54.62 minutes
• 4] 50.62 minutes

A long distance runner run 9 laps of a 400 metres track everyday. His timings (in min) for four consecutive days are 88, 96, 89 and 87 respectively. On an average, how many metres/minutes does the runner cover ?

• 1] 17.78 m/min
• 2] 40 m/min
• 3] 90 m/min
• 4] None of these

A bus covered a certain distance from village A to village B at the speed of 60 km/hr. However on its return journey it got stuck in traffic and covered the same distance at the speed of 40 km/hr and took 2 hours more to reach its destination. What is the distance covered between villages A and B ?

• 1] 200 km
• 2] 240 km
• 3] 260 km
• 4] Cannot be determined
• 5] None of these