Quiz Discussion

A train approaches a tunnel AB. Inside the tunnel is a cat located at a point that is \(\frac{3}{8}\) of the distance AB measured from entrance A. When the train whistles, that cat runs. If the cat moves to entrance A of the tunnel, the train catches the cat exactly at the entrance. If the cat moves to exit B, the train catches the cat at exactly the exit. The ratio of the speed of the train to that of the cat is of the order :

• 1] 3 :1
• 2] 4 : 1
• 3] 5 : 1
• 4] None of these

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

If a train runs at 40 kmph, it reaches its destination late by 11 minutes but if it runs at 50 kmph, it is late by 5 min only. The correct time for the train to complete its journey is :

• 1] 13 min
• 2] 15 min
• 3] 19 min
• 4] 21 min

Each wheel of a car is making 5 revolutions per second. If the diameter of a wheel is 84 cm, then the speed of the car in cm/sec would be :

• 1] 420 cm/sec
• 2] 264 cm/sec
• 3] 1000 cm/sec
• 4] 1320 cm/sec

Amit starts from a point A and walks to another points B and then returns from B to A by his car and thus takes a total time of 6 hours and 45 min. If he had driven both ways in his car, he would have taken 2 hours less. How long would it take for him to walk both ways ?

• 1] 7 hrs 45 min
• 2] 8 hrs 15 min
• 3] 8 hrs 30 min
• 4] 8 hrs 45 min

A person travels three equal distance at a speed of x km/hr, y km/hr and z km/hr respectively. What is the average speed for the whole journey ?

• 1]

  \(\frac{{xyz}}{{3\left( {xy + yz + zx} \right)}}\)    km/hr

• 2]

  \(\frac{{xyz}}{{\left( {xy + yz + zx} \right)}}\)    km/hr

• 3]

  \(\frac{{\left( {xy + yz + zx} \right)}}{{xyz}}\)    km/hr

• 4]

  \(\frac{{3xyz}}{{\left( {xy + yz + zx} \right)}}\)    km/hr

A train 100 m long is running at the speed of 30 km/hr. The time (in second) in which it passes a man standing near the railway line is :

• 1] 10 seconds
• 2] 11 seconds
• 3] 12 seconds
• 4] 15 seconds

A man takes 50 minutes to cover a certain distance at a speed of 6 km/hr. If he walks with a speed of 10 km/hr, he covers the same distance in :

• 1] 10 min
• 2] 20 min
• 3] 30 min
• 4] 40 min

Two persons A and B start simultaneously from P and Q respectively. A meets B at a distance of 60m from P. After A reaches Q and B reaches P, they turn around and start walking in opposite direction, now B meets A at a distance of 40m from Q. Find distance between P and Q?

• 1] 160 m
• 2] 100 m
• 3] 140 m
• 4] 105 m
• 5] None of These

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