Quiz Discussion

A plane flying north at 500 mph passes over a city at 12 noon. A plane flying east at the same altitude passes over the same city at 12.30 pm. The plane is flying east at 400 mph. To the nearest hundred miles, how far apart are the two planes at 2 pm ?

• 1] 600 miles
• 2] 1000 miles
• 3] 1100 miles
• 4] 1200 miles
• 5] 1300 miles

Two planes move along a circle of circumference 1.2 km with constant speeds. When they move in different directions, they meet every 15 seconds and when they move in the same direction, one plane overtakes the other every 60 seconds. Find the speed of the slower plane.

• 1] 0.04 km/s
• 2] 0.03 km/s
• 3] 0.05 km/s
• 4] 0.02 km/s
• 5] None of these

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 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

A train passes two bridges of length 500 metres and 250 metres in 100 seconds and 60 seconds respectively. The length of the train is :

• 1] 125 metres
• 2] 250 metres
• 3] 120 metres
• 4] 152 metres

A journey of 192 km between two cities take 2 hours less by a fast train than by a slow train. If the average speed of the slow train is 16 km/hr less than that of the fast train, the average speed of the fast train is :

• 1] 32 km/hr
• 2] 36 km/hr
• 3] 48 km/hr
• 4] 64 km/hr

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

A monkey climbs a 60 m high pole. In first minute he climbs 6 m and slips down 3 m in the next minute. How much time is required by it to reach the top?

• 1] 35 minutes
• 2] 33 minutes
• 3] 37 minutes
• 4] 40 minutes

A person can row a boat d km upstream and the same distance downstream in 5 hours 15 minutes. Also, he can row the boat 2d km upstream in 7 hours. How long will it take to row the same distance 2d km downstream?

• 1]

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

• 2]

  7 hours

• 3]

  \(\frac{{29}}{{4}}\) hours

• 4]

  \(\frac{{7}}{{2}}\) hours

In a race of one kilometre. A gives B a start of 100 metres and still wins by 20 seconds. But if A gives B a start of 25 seconds, B wins by 50 metres. The time taken by A to run kilometre is :

• 1]

  17 sec

• 2]

  \(\frac{{500}}{{29}}{ \text{sec}}\)

• 3]

  \(\frac{{1200}}{{29}}{ \text{sec}}\)

• 4]

  \(\frac{{700}}{{29}}{ \text{sec}}\)