Quiz Discussion

A and B start from the same point and in the same direction at 7 am to walk around a rectangular field 400 m × 300 m. A and B walk at the rate of 3 km/hr and 2.5 km/hr respectively. How many times shall they cross each other if they continue to walk till 12.30 pm ?

• 1] Not even once
• 2] Once
• 3] Twice
• 4] Thrice

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 person travels from P to Q at a speed of 40 kmph and returns by increasing his speed by 50%. What is his average speed for both the trips ?

• 1] 36 kmph
• 2] 45 kmph
• 3] 48 kmph
• 4] 50 kmph

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

Three runners A, B and C run a race, with runner A finishing 12 metres ahead of runner B and 18 metres ahead of runner C, in another race of same type runner B finished 8 metres ahead of runner C. Each runner travels the entire distance at a constant speed. The length of the race is :

• 1] 36 metres
• 2] 48 metres
• 3] 60 metres
• 4] 72 metres

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

I started on my bicycle at 7 am to reach a certain place. After going a certain distance, my bicycle went out of order. Consequently, I rested for 35 minutes and came back to my house walking all the way. I reached my house at 1 pm. If my cycling speed is 10 kmph and my walking speed is 1 kmph, then on my bicycle I covered a distance of :

• 1]

  \(4\frac{61}{66}\) km

• 2]

  \(13\frac{4}{9}\) km

• 3]

  \(14\frac{3}{8}\) km

• 4]

  \(15\frac{10}{21}\) km

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 truck covers a distance of 550 metres in 1 minute whereas a bus covers a distance of 33 kms in 45 minutes. The ratio of their speed is :

• 1] 4 : 3
• 2] 3 : 5
• 3] 3 : 4
• 4] 50 : 3

A, B and C start together from the same place to walk round a circular path of length 12km. A walks at the rate of 4 km/h, B 3 km/h and C \(\frac{3}{2}\) km/h. They will meet together at the starting place at the end of:

• 1] 10 hours
• 2] 12 hours
• 3] 15 hours
• 4] 24 hours