Quiz Discussion

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]

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

How long must a driver take to drive the final 70 miles of a trip if he wants to average 50 miles an hour for the entire trip and during the first part of the trip he drove 50 miles in \(1\frac{1}{2}\) hours ?

• 1] 54 min
• 2] 1 hr
• 3] 66 min
• 4] 70 min

A train 300 m long passed a man walking along the line in the same direction at the rate of 3 km/hr in 33 sec. The speed of the train is :

• 1]

  30 km/hr

• 2]

  32 km/hr

• 3]

  \(32\frac{8}{{11}}\)  km/hr

• 4]

  \(35\frac{8}{{11}}\)  km/hr

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

A hunter fired two shots from the branch of a tree at an interval of 76 seconds. A tiger separating too fast hears the two shots at an interval of 83 seconds. If the velocity of the sound is 1195.2 km/h, then find the speed of the tiger.

• 1] 112.8 km/h
• 2] 100.8 km/h
• 3] 80.16 km/h
• 4] 85.16 km/h
• 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

Mr A started half an hour later than usual for the marketplace. But by increasing his speed to \(\frac{3}{2} \)times his usual speed he reached 10 minutes earlier than usual. What is his usual time for this journey?

• 1] 1 hours
• 2] 2 hours
• 3] 3 hours
• 4] 45 minutes
• 5] None of these

Two boats A and B start towards each other from two places, 108 km apart. Speed of the boats A and B in still water are 12 km/h and 15 km/h respectively. If A proceeds down and B up the stream, they will meet after:

• 1] 4.5 hours
• 2] 4 hours
• 3] 5.4 hours
• 4] 6 hours

A plane left half an hour later than the scheduled time and in order to reach its destination 1500 kilometers away in time, it had to increase its speed by 33.33 percent over its usual speed. Find its increased speed.

• 1] 250 kmph
• 2] 500 kmph
• 3] 750 kmph
• 4] 1000 kmph
• 5] 1200 kmph