## Speed, Time and Distance

#### Speed, Time and Distance

1. The speed of a bus is 72 km/hr. The distance covered by the bus in 5 seconds is
1. 100 m
2. 60 m
3. 50 m
4. 74.5 m

1. Speed of bus = 72 kmph

 = 72 × 5 metre/second 18

= 20 metre/second
∴  Required distance
= 20 × 5 = 100 metre

##### Correct Option: A

Speed of bus = 72 kmph

 = 72 × 5 metre/second 18

= 20 metre/second
∴  Required distance
= 20 × 5 = 100 metre

1. A person started his journey in the morning.
 At 11 a.m. he covered 3 of the journey and on the 8
 same day at 4.30 p.m. he covered 5 of the journey. 6

He started his journey at
1. 6.00 a.m.
2. 3.30 a.m.
3. 7.00 a.m.
4. 6.30 a.m.

1. Difference of time = 4.30 p.m – 11.a.m.

 = 5 1 hours = 11 hours 2 2

 Distance covered in 11 hrs 2

 = 5 − 3 = 20 − 9 = 11 part 6 8 24 24

 ∵ 11 part of the journey is covered in 11 hours 24 2

 ⇒ 3 part of the journey is covered in 8

 = 11 × 24 × 3 = 9 hours 2 11 8 2

 = 4 1 hours. 2

Clearly the person started at 6.30 a.m.

##### Correct Option: D

Difference of time = 4.30 p.m – 11.a.m.

 = 5 1 hours = 11 hours 2 2

 Distance covered in 11 hrs 2

 = 5 − 3 = 20 − 9 = 11 part 6 8 24 24

 ∵ 11 part of the journey is covered in 11 hours 24 2

 ⇒ 3 part of the journey is covered in 8

 = 11 × 24 × 3 = 9 hours 2 11 8 2

 = 4 1 hours. 2

Clearly the person started at 6.30 a.m.

1. A and B travel the same distance at speed of 9 km/hr and 10 km/hr respectively. If A takes 36 minutes more than B, the distance travelled by each is
1. 48 km
2. 54 km
3. 60 km
4. 66 km

1. Let the distance between A and B be x km, then

 x − x = 36 = 3 9 10 60 5

 ⇒ x = 3 90 5

 ⇒ x = 3 × 90 = 54 km. 5

Second Method :
Here, S1 = 9, t1 = x
 S2 = 10, t2 = x − 36 60

S1t1 = S2t2
 9 × x = 10 x − 36 60

9x = 10x – 6x = 6
Distance travelled
= 9 × 6 = 54 km

##### Correct Option: B

Let the distance between A and B be x km, then

 x − x = 36 = 3 9 10 60 5

 ⇒ x = 3 90 5

 ⇒ x = 3 × 90 = 54 km. 5

Second Method :
Here, S1 = 9, t1 = x
 S2 = 10, t2 = x − 36 60

S1t1 = S2t2
 9 × x = 10 x − 36 60

9x = 10x – 6x = 6
Distance travelled
= 9 × 6 = 54 km

1. A man riding his bicycle covers 150 metres in 25 seconds. What is his speed in km per hour ?
1. 25
2. 21.6
3. 23
4. 20

1.  Speed = 150 = 6 m/sec 25

 = 6 × 18 = 108 = 21.6 kmph 5 5

##### Correct Option: B

 Speed = 150 = 6 m/sec 25

 = 6 × 18 = 108 = 21.6 kmph 5 5

1. A train is moving with the speed of 180 km/hr. Its speed (in metres per second) is :
1. 5
2. 40
3. 30
4. 50

1. Speed = 180 kmph

 = 180 × 5 m/sec = 50 m/sec 18 ∵   1 km/hr = 5 m/s 18

##### Correct Option: D

Speed = 180 kmph

 = 180 × 5 m/sec = 50 m/sec 18 ∵   1 km/hr = 5 m/s 18