Quiz Discussion

A car traveling with \(\frac{5}{7}\) of its usual speed covers 42 km in 1 hr 40 min 48 sec. What is the usual speed of the car?

• 1]

  \(17\frac{6}{7}\) km/hr

• 2]

  35 km/hr

• 3]

  25 km/hr

• 4]

  30 km/hr

A man goes downstream with a boat to some destination and returns upstream to his original place in 5 hours. If the speed of the boat in still water and the stream are 10 kmph and 4 kmph respectively, the distance of the destination from the starting place is:

• 1] 16 km
• 2] 18 km
• 3] 21 km
• 4] 25 km

A car goes 10 meters in a second. Find its speed in km/hour.

• 1] 40 km/hr
• 2] 32 km/hr
• 3] 48 km/hr
• 4] 36 km/hr

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

A train increases its normal speed by 12.5% and reaches its destination 20 min earlier. What is the actual time taken by the train in the journey ?

• 1] 145 minutes
• 2] 160 minutes
• 3] 180 minutes
• 4] 220 minutes

Roorkee express normally reaches its destination at 50 km/h in 30 hours. Find the speed at which it travels to reduce the time by 10 hours?

• 1] 38 km/h
• 2] 76 km/h
• 3] 75 km/h
• 4] 60 km/h

A train travels at a speed of 30 km/hr for 12 minutes and at a speed of 45 km/hr for the next 8 minutes. The average speed of the train for this journey is :

• 1] 30 km/hr
• 2] 36 km/hr
• 3] 37.5 km/hr
• 4] 48 km/hr

Two boats go downstream from point X to Y. The faster boat covers the distance from X to Y, 1.5 times as fast as slower boat. It is known that for every hour slower boat lags behinds the faster boat by 8 km. however, if they go upstream, then the faster boat covers the distance from Y to X in half the time as the slower boat. Find the speed of the faster boat in still water?

• 1] 12 kmph
• 2] 20 kmph
• 3] 24 kmph
• 4] 25 kmph
• 5] None of these

An individual is cycling at a speed of 25 km per hour. He catches his predecessor who had started earlier in two hours. What is the speed of his predecessor who had started 3 hours earlier ?

• 1] 15 kmph
• 2] 12 kmph
• 3] 10 kmph
• 4] 8 kmph

P and Q are 27 km away. Two trains with speed of 24 km/hr and 18 km/hr respectively start simultaneously from P and Q and travel in the same direction. They meet at a point R beyond Q. Distance QR is :

• 1] 126 km
• 2] 81 km
• 3] 48 km
• 4] 36 km