Quiz Discussion

If A travels to his school from his house at the speed of 3 km/h, then he reaches the school 5 minutes late. If he travels at the speed of 4 km/h, he reaches the school 5 minutes earlier than school time. The distance of his school from his house is:

• 1] 1 km
• 2] 2 km
• 3] 3 km
• 4] 4 km

The speed of A and B are in the ratio 3 : 4. A takes 20 minutes more than B to reach a destination. Time in which A reach the destination?

• 1]

  \(1\frac{1}{3}\) hours

• 2]

  2 hours

• 3]

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

• 4]

  \(1\frac{2}{3}\) hours

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 starts 3 Minutes after B for a place 4.5 km distant. B, on reaching his destination, immediately returns and after walking a km meets A. If A can walk 1 Km in 18 minutes,then what is B's speed?

• 1] 4 km/h
• 2] 6 km/h
• 3] 7 km/h
• 4] 5 km/h

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

A thief sees a jeep at a distance of 250 m, coming towards him at 36 km/h. Thief takes 5 seconds to realize that there is nothing but the police is approaching him by the jeep and start running away from police at 54 km/h. But police realise after 10 second, when the thief starts running away, that he is actually a thief and gives chase at 72 km/h. How long after thief saw police did catchup with him and what is the distance police had travel to do so?

• 1] 50 s, 1000 m
• 2] 65 s, 1150 m
• 3] 65 s, 1300 m
• 4] 45 s, 1050 m
• 5] None of these

In a race of 200 meters, B can gives a start of 10 meters to A, and C can gives a start of 20 meters to B. The starts that C can gives to A, in the same race is:

• 1] 30 meters
• 2] 25 meters
• 3] 29 meters
• 4] 27 meters

A man takes 50 minutes to cover a certain distance at a speed of 6 km/hr. If he walks with a speed of 10 km/hr, he covers the same distance in :

• 1] 10 min
• 2] 20 min
• 3] 30 min
• 4] 40 min

The distance between two places R and S is 42 km. Anita starts from R with a uniform speed of 4 km/hr towards S and at the same time Romita starts from S towards R also with some uniform speed. They meet each other after 6 hours. The speed of Romita is :

• 1] 18 km/hr
• 2] 20 km/hr
• 3] 3 km/hr
• 4] 8 km/hr

Two guns were fired from the same place at an interval of 8 minutes. A person approaching the place observes that 5 minutes 52 seconds have elapsed between the hearing of the sound of the two guns. If the velocity of the sound is 330 m/sec, the man was approaching the place at what speed (in km/hr) ?

• 1] 24 km/hr
• 2] 27 km/hr
• 3] 30 km/hr
• 4] 36 km/hr