Speed, Time and Distance
 A speed of 45 km per hour is the same as

 12.5 metre/seccond
 13 metre/seccond
 15 metre/seccond
 12 metre/seccond

View Hint View Answer Discuss in Forum
Speed = 45 kmph
= 45 × 1000 metre/second 60 × 60 = 45 × 5 metre/second 18
= 12.5 metre/secondCorrect Option: A
Speed = 45 kmph
= 45 × 1000 metre/second 60 × 60 = 45 × 5 metre/second 18
= 12.5 metre/second
 The distance between place A and B is 999 km. An express train leaves place A at 6 am and runs at a speed of 55.5 km/hr. The train stops on the way for 1 hour 20 minutes. It reaches B at

 1.20 am
 12 pm
 6 pm
 11 pm

View Hint View Answer Discuss in Forum
Time taken in covering 999 km
= 999 = 18 hours 55.5
∴ Required time = 18 hours + 1 hour 20 minutes
= 19 hours 20 minutes
i.e. 1 : 20 amCorrect Option: A
Time taken in covering 999 km
= 999 = 18 hours 55.5
∴ Required time = 18 hours + 1 hour 20 minutes
= 19 hours 20 minutes
i.e. 1 : 20 am
 Two cars are moving with speed v_{1}, v_{2} towards a crossing along two roads. If their distance from the crossing be 40 metres and 50 metres at an instant of time then they do not collide if their speed are such that

 v_{1} : v_{2} = 16 : 25
 v_{1} : v_{2} ≠ 4 : 5
 v_{1} : v_{2} ≠ 5 : 4
 v_{1} : v_{2} = 25 : 16

View Hint View Answer Discuss in Forum
Let time taken be equali.e., 40 = 50 , then V_{1} V_{2}
they will collide i.e. cars will reach at the same time.∴ V_{1} ≠ 40 = 4 V_{2} 50 5 Correct Option: B
Let time taken be equali.e., 40 = 50 , then V_{1} V_{2}
they will collide i.e. cars will reach at the same time.∴ V_{1} ≠ 40 = 4 V_{2} 50 5
 A, B, C walk 1 km in 5 minutes, 8 minutes and 10 minutes respectively. C starts walking from a point, at a certain time, B starts from the same point 1 minutes later and A starts from the same point 2 minutes later than C. Then A meets B and C after


5 min, 2 min 3  1 min, 2 min
 2 min, 3 min

4 min, 3 min 3


View Hint View Answer Discuss in Forum
A’s speed = 1000 = 200 m/minute 5 B’s speed = 1000 = 125 m/minute 8 C’s speed = 1000 = 100 m/minute 10
Distance covered by C in 2 minutes = 200 metre
Distance covered by B in 1 minute = 125 metre
Relative speed of A with respect to C = 100 metre∴ Time = 200 = 2 minutes 100
Relative speed of A with respect ot B = 75 metre∴ Time = 125 = 5 minutes 75 3 Correct Option: A
A’s speed = 1000 = 200 m/minute 5 B’s speed = 1000 = 125 m/minute 8 C’s speed = 1000 = 100 m/minute 10
Distance covered by C in 2 minutes = 200 metre
Distance covered by B in 1 minute = 125 metre
Relative speed of A with respect to C = 100 metre∴ Time = 200 = 2 minutes 100
Relative speed of A with respect ot B = 75 metre∴ Time = 125 = 5 minutes 75 3

He travelled onethird of the trip by car and the rest by train. The distance (in km) travelled by train wasRam travelled 1200 km by air which formed 2 of his trip. 5

 480
 800
 1600
 1800

View Hint View Answer Discuss in Forum
Total distance of trip
= 1200 × 5 = 3000 km 2
Part of journey covered by train= 1 − 2 − 1 = 15 − 6 − 5 = 4 5 3 15 15 ∴ Distance covered by train = 3000 × 4 15
= 800 kmCorrect Option: B
Total distance of trip
= 1200 × 5 = 3000 km 2
Part of journey covered by train= 1 − 2 − 1 = 15 − 6 − 5 = 4 5 3 15 15 ∴ Distance covered by train = 3000 × 4 15
= 800 km