Quiz Discussion

Rani goes to school from her house in 30 minutes. Raja takes 45 minutes in covering the same distance. Find the ratio between time taken by Rani and Raja ?

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

There are 8 equidistant points A, B, C, D, E, F, G and H in the clockwise direction on the periphery of a circle. In a time interval t, a person reaches from A to C with uniform motion while another person reaches the point E from the point B during the same time interval with uniform motion. Both the persons move in the same direction along the circumference of the circle and start at the same instant. How much time after the start, will the two persons meet each other ?

• 1] 4t
• 2] 7t
• 3] 9t
• 4] Never

A man can row 15 km/h in still water and he finds that it takes him twice as much time to row up than as to row down the same distance in the river. The speed of current (in km/h) :

• 1] 6 km/h
• 2] 6.5 km/h
• 3] 4.5 km/h
• 4] 5 km/h

Two trains 105 meters and 90 meters long, run at the speeds of 45 kmph and 72 kmph respectively, in opposite directions on parallel tracks. The time which they take to cross each other, is:

• 1] 8 seconds
• 2] 6 seconds
• 3] 7 seconds
• 4] 5 seconds

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

An aeroplane flies from place A to place B at the speed of 500 km/hr. On the return journey, its speed is 700 km/hr. The average speed of the aeroplane for the entire journey is ?

• 1]

  \(566\frac{2}{3}{ \text{ km/hr}}\)

• 2]

  \(583\frac{1}{3}{ \text{ km/hr}}\)

• 3]

  \(583\frac{2}{3}{ \text{ km/hr}}\)

• 4]

  \(600{ \text{ km/hr}}\)

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

A plan left 40 minutes late due to bad whether and order to reach its destination 1600 km away in time, it had increase its speed by 400 kmph from its usual speed. Find the usual speed of the plane?

• 1] 600 km/hour
• 2] 400 km/hour
• 3] 1000 km/hour
• 4] 800 km/hour

Two boys A and B start at the same time to ride from Delhi to Meerut, 60 km away. A travels 4 km an hours slower than B, B reaches Meerut and at once turns back meeting A, 12 km from Meerut. A's rate was :

• 1] 4 km/hr
• 2] 8 km/hr
• 3] 12 km/hr
• 4] 16 km/hr

A runs \(\frac{7}{4}\) times as fast as B. If A gives B a start of 300 m, how far must the winning post be if both A and B have to end the race at the same time?

• 1] 1400 m
• 2] 700 m
• 3] 350 m
• 4] 210 m