Quiz Discussion

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

If two incorrect watches are set at 12:00 noon at correct time, when will both watches show the correct time for the first time given that the first watch gains 1 min in one hour and second watch looses 4 min in two hours.

• 1] 6 PM, 25 days later
• 2] 12 noon, 30 days later
• 3] 12 noon, 15 days later
• 4] 6 AM, 45 days later
• 5] None of these

Train A travelling at 60 km/hr leaves Mumbai for Delhi at 6 pm. Train B travelling at 90 km/hr also leaves Mumbai for Delhi at 9 pm. Train C leaves Delhi for Mumbai at 9 pm. If all the three trains meet at the same time between Mumbai and Delhi, then what is the speed of train C if the distance between Delhi and Mumbai is 1260 km ?

• 1] 60 km/hr
• 2] 90 km/hr
• 3] 120 km/hr
• 4] 135 km/hr

The speeds of three cars are the ratio 2 : 3 : 4. The ratio of the taken by these cars to travel the same distance is :

• 1] 2 : 3 : 4
• 2] 4 : 3 : 2
• 3] 4 : 3 : 6
• 4] 6 : 4 : 3

A train approaches a tunnel AB. Inside the tunnel, a cat is located at a point i.e. \(\frac{5}{{12}}\) of the distance AB measured from entrance A. When the train whistles the Cat runs. If the cat moves to exit B, the train catches the cat exactly at the exit. The speed of the train is greater than the speed of the cat by what order?

• 1] 1 : 6
• 2] 3 : 5
• 3] 6 : 1
• 4] 5 : 4
• 5] None of these

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

A dog after traveling 50 km meets a swami who counsels him to go slower. He then proceeds at \(\frac{3}{4} \)of his former speed and arrives at his destination 35 min late. Had the meeting occurred 24 km further the dog would have reached its destination 25 min late. The speed of the dog is:

• 1] 48 kmph
• 2] 36 kmph
• 3] 54 kmph
• 4] 58 kmph

A is 10 miles west of B. C is 30 miles north of B. D is 20 miles east of C. What is the distance from A to D ?

• 1]

  10 miles

• 2]

  30 miles

• 3]

  \(10\sqrt {10}  \) miles

• 4]

  \(10\sqrt {13}  \) miles

• 5]

  \(30\sqrt {2}  \) miles

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

Running at \(\frac{5}{4}\) of his usual speed, an athlete improves his timing by 5 minutes. The time he usually takes to run the same distance is:

• 1] 30 min.
• 2] 28 min.
• 3] 25 min.
• 4] 23 min.