Speed, Time and Distance

is 25 minutes late. His usual time to cover this distance isWalking at 6 th of his usual speed a man 7

 2 hours 30 minutes
 2 hours 15 minutes
 2 hours 25 minutes
 2 hours 10 minutes

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Time and speed are inversely proportional.
∴ 7 × Usual time – Usual time = 25 minutes 6 ⇒ 7 − 1 = 25 minutes 6 ⇒ Usual time × 1 = 25 minutes 6
∴ Usual time = 25 × 6
= 150 minutes
= 2 hours 30 minutes
Second Method :
Here, A = 6, B = 7,t = 25 = 5 hrs. 60 12 Usual time = A × time Diff. of A and B = 6 × 5 = 5 hrs. (7 − 6) 12 2
= 2 hours 30 minutesCorrect Option: A
Time and speed are inversely proportional.
∴ 7 × Usual time – Usual time = 25 minutes 6 ⇒ 7 − 1 = 25 minutes 6 ⇒ Usual time × 1 = 25 minutes 6
∴ Usual time = 25 × 6
= 150 minutes
= 2 hours 30 minutes
Second Method :
Here, A = 6, B = 7,t = 25 = 5 hrs. 60 12 Usual time = A × time Diff. of A and B = 6 × 5 = 5 hrs. (7 − 6) 12 2
= 2 hours 30 minutes

Walking at 3 of his usual speed, 4
cover the same distance, (in hours) isa man is 1 1 hours late. His usual time to 2


4 1 2  4

5 1 2  5


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Time and speed are inversely proportional.
∴ 4 of usual time –usual time 3 = 3 2 ⇒ 1 × usual time = 3 3 2 ∴ Usual time = 3 × 3 = 9 2 2 = 4 1 hours 2
Second Method :Here, A = 3, B = 4, t = 3 2 Usual time = A × time Diff. of A and B = 3 × 3 (4 − 3) 2 = 4 1 hrs. 2 Correct Option: A
Time and speed are inversely proportional.
∴ 4 of usual time –usual time 3 = 3 2 ⇒ 1 × usual time = 3 3 2 ∴ Usual time = 3 × 3 = 9 2 2 = 4 1 hours 2
Second Method :Here, A = 3, B = 4, t = 3 2 Usual time = A × time Diff. of A and B = 3 × 3 (4 − 3) 2 = 4 1 hrs. 2

a man reaches his office 20 minutes later than his usual time. The usual time taken by him to reach his office isBy walking at 3 of his usual speed, 4

 75 minutes
 60 minutes
 40 minutes
 30 minutes

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4 of usual time = Usual time + 20 minutes 3 ∴ 1 of usual time = 20 minutes 3
⇒ Usual time = 20 × 3
= 60 minutes
Second Method :
Here, A = 3, B= 4, t = 20 minutesUsual time taken = A × time Diff. of A and B = 3 × 20 = 60 minutes (4 − 3) Correct Option: B
4 of usual time = Usual time + 20 minutes 3 ∴ 1 of usual time = 20 minutes 3
⇒ Usual time = 20 × 3
= 60 minutes
Second Method :
Here, A = 3, B= 4, t = 20 minutesUsual time taken = A × time Diff. of A and B = 3 × 20 = 60 minutes (4 − 3)
 Walking at threefourth of his usual speed, a man covers a certain distance in 2 hours more than the time he takes to cover the distance at his usual speed. The time taken by him to cover the distance with his usual speed is

 4.5 hours
 5.5 hours
 6 hours
 5 hours

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4 ×usual time – usual time = 2 3 ⇒ 1 usual time = 2 3
∴ Usual time = 2 × 3 = 6 hours
Second Method :Here, A = 3 , time= 2 hrs. B 4 Usual time
=A × time Diff. of A and B = 3 × 2 = 6 hours (4 − 3) Correct Option: C
4 ×usual time – usual time = 2 3 ⇒ 1 usual time = 2 3
∴ Usual time = 2 × 3 = 6 hours
Second Method :Here, A = 3 , time= 2 hrs. B 4 Usual time
=A × time Diff. of A and B = 3 × 2 = 6 hours (4 − 3)

42 km in 1 hour 40 min 48 sec. What is the usual speed of the car?A car travelling with 5 of its usual speed covers 7


17 6 km/hr 7  35 km/hr
 25 km/hr
 30 km/hr


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1 hr 40 min 48 sec
= 1 hr 40 + 48 min 60 = 1 hr 40 + 4 min 5 = 1 hr 204 min 5 = 1 + 204 hr 300 = 504 hr 300 ∴ Speed = 42 504 300
= 25 kmphNow, 5 ×usual speed = 25 7 ∴ Usual speed = 25 × 7 5
= 35 kmphCorrect Option: B
1 hr 40 min 48 sec
= 1 hr 40 + 48 min 60 = 1 hr 40 + 4 min 5 = 1 hr 204 min 5 = 1 + 204 hr 300 = 504 hr 300 ∴ Speed = 42 504 300
= 25 kmphNow, 5 ×usual speed = 25 7 ∴ Usual speed = 25 × 7 5
= 35 kmph