Speed, Time and Distance

A man covers 2 of the total journey 15
10 km on foot. His total journey (in km) isby train, 9 by bus and the remaining 20

 15.6
 24
 16.4
 12.8

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Let the total journey be of x km, then
2x + 9x + 10 = x 15 20 ⇒ x − 2x − 9x = 10 15 20 ⇒ 60x − 8x − 27x = 10 60 ⇒ 25x = 10 60 ⇒ x = 60 × 10 = 24 km 25 Correct Option: B
Let the total journey be of x km, then
2x + 9x + 10 = x 15 20 ⇒ x − 2x − 9x = 10 15 20 ⇒ 60x − 8x − 27x = 10 60 ⇒ 25x = 10 60 ⇒ x = 60 × 10 = 24 km 25
 A speed of 30.6 km/.hr is the same as

 8.5 m/sec.
 l0 m/sec.
 12 m/sec.
 15.5 m/sec.

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30.6 kmph
30.06 × 5 m/sec. 18
= 8.5 m/secCorrect Option: A
30.6 kmph
30.06 × 5 m/sec. 18
= 8.5 m/sec
 A man rides at the rate of 18 km/ hr, but stops for 6 mins. to change horses at the end of every 7th km. The time that he will take to cover a distance of 90 km is

 6 hrs.
 6 hrs. 12 min.
 6 hrs. 18 min.
 6 hrs. 24 min.

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90 km = 12 × 7km + 6 km. To
cover 7 km total time taken = 7 8 hours + 6 min. = 88 min. So, 3
(12 × 7 km) would be covered in12 × 88 min. and remaining 6 km is 6 hrs or 20 min 3 18 ∴ Total time = 1056 + 20 3 = 1116 hours = 6 1 hours 3 × 60 5
= 6 hours 12 minutes.Correct Option: B
90 km = 12 × 7km + 6 km. To
cover 7 km total time taken = 7 8 hours + 6 min. = 88 min. So, 3
(12 × 7 km) would be covered in12 × 88 min. and remaining 6 km is 6 hrs or 20 min 3 18 ∴ Total time = 1056 + 20 3 = 1116 hours = 6 1 hours 3 × 60 5
= 6 hours 12 minutes.
 A train covers a certain distance in 210 minutes at a speed of 60 kmph. The time taken by the train, to cover the same distance at a speed of 80 kmph is :


3 5 hours 8 
2 5 hours 8 
4 5 hours 8  3 hours


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Speed of train = 60 kmph
Time = 210 minutes= 210 hours 60 or 7 hours 2 Distance covered = 60 × 7 = 210 km 2 Time taken at 80 kmph = 210 = 21 hours 80 8 = 2 5 hours 8
Second Method :Here, S_{1} 60, t_{1} = 210 hrs 60
S_{2} = 80, t_{2} = ?
S_{1}t_{1} = S_{2}t_{2}60 × 210 = 80 × t_{2} 60 t_{2} = 2 5 hrs 8 Correct Option: B
Speed of train = 60 kmph
Time = 210 minutes= 210 hours 60 or 7 hours 2 Distance covered = 60 × 7 = 210 km 2 Time taken at 80 kmph = 210 = 21 hours 80 8 = 2 5 hours 8
Second Method :Here, S_{1} 60, t_{1} = 210 hrs 60
S_{2} = 80, t_{2} = ?
S_{1}t_{1} = S_{2}t_{2}60 × 210 = 80 × t_{2} 60 t_{2} = 2 5 hrs 8

in km/hour becomesThe speed 3 1 m/sec when expressed 3

 8
 9
 10
 12

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∵ 1 m/sec = 18 kmph 5 ∴ 10 m/sec 3 = 18 × 10 = 12 kmph 5 3 Correct Option: D
∵ 1 m/sec = 18 kmph 5 ∴ 10 m/sec 3 = 18 × 10 = 12 kmph 5 3