Speed, Time and Distance
- In a race of 800 metres, A can beat B by 40 metres. In a race of 500 metres, B can beat C by 5 metres. In a race of 200 metres, A will beat C by
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According to the question,
∴ When A runs 800 metres, B runs 760 metres
∴ When A runs 200 metres, B runs= 760 × 200 = 190 metres 800
Again, when B runs 500 metres, C runs 495 metres.
∴ When B runs 190 metres, C runs= 495 × 190 = 188.1 metres 500
∴ Hence, A will beat C by
200 – 188.1 = 11.9 metres in a race of 200 metres.Correct Option: A
According to the question,
∴ When A runs 800 metres, B runs 760 metres
∴ When A runs 200 metres, B runs= 760 × 200 = 190 metres 800
Again, when B runs 500 metres, C runs 495 metres.
∴ When B runs 190 metres, C runs= 495 × 190 = 188.1 metres 500
∴ Hence, A will beat C by
200 – 188.1 = 11.9 metres in a race of 200 metres.
- In a race of 1000 m, A can beat B by 100m. In a race of 400 m, B beats C by 40m. In a race of 500m. A will beat C by
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When A runs 1000m, B runs 900m.
∴ When A runs 500m, B runs 450 m.
Again, when B runs 400m, C runs 360 m.
∴ When B runs 450m, C runs= 360 × 450 = 405 metres 400
Required distance = 500 – 405
= 95 metresCorrect Option: A
When A runs 1000m, B runs 900m.
∴ When A runs 500m, B runs 450 m.
Again, when B runs 400m, C runs 360 m.
∴ When B runs 450m, C runs= 360 × 450 = 405 metres 400
Required distance = 500 – 405
= 95 metres
- A man can reach a certain place in 30 hours.
10 km less in that time. Find his speed per hour.If he reduces his speed by 1 th, he goes 15
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Let the speed of man be x kmph.
∴ 30x − 30 
x − x 
= 10 15 ⇒ 30 x − x + x = 10 15 ⇒ x = 10 15 30 ⇒ x = 150 = 5 kmph 30 Correct Option: D
Let the speed of man be x kmph.
∴ 30x − 30 x − x = 10 15 ⇒ 30 x − x + x = 10 15 ⇒ x = 10 15 30 ⇒ x = 150 = 5 kmph 30
- In a race of one kilometre, A gives B a start of 100 metres and still wins by 20 seconds. But if A gives B a start of 25 seconds, B wins by 50 metres. The time taken by A to run one kilometre is
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Let A take x seconds in covering 1000m and b takes y seconds
According to the question,x + 20 = 900 y 1000 ⇒ x + 20 = 9y ...(i) 10 and, 950 x + 25 = y ...(ii) 1000
From equation (i),10x + 200 = y 9 9 ⇒ 10x + 200 = 950x + 25 9 9 1000 ⇒ 10x + 200 = 19x + 25 9 9 20 ⇒ 10x − 19x = 25 − 200 9 20 9 = 200x − 171x = 225 − 200 180 9 ⇒ 29x = 25 180 9 ⇒ x = 25 × 180 = 500 seconds. 9 29 29 Correct Option: B
Let A take x seconds in covering 1000m and b takes y seconds
According to the question,x + 20 = 900 y 1000 ⇒ x + 20 = 9y ...(i) 10 and, 950 x + 25 = y ...(ii) 1000
From equation (i),10x + 200 = y 9 9 ⇒ 10x + 200 = 950x + 25 9 9 1000 ⇒ 10x + 200 = 19x + 25 9 9 20 ⇒ 10x − 19x = 25 − 200 9 20 9 = 200x − 171x = 225 − 200 180 9 ⇒ 29x = 25 180 9 ⇒ x = 25 × 180 = 500 seconds. 9 29 29
- A runs twice as fast as B and B runs thrice as fast as C. The distance covered by C in 72 minutes, will be covered by A in :
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Ratio of the speed of A, B and
C = 6 : 3 : 1
⇒ Ratio of the time taken= 1 : 1 : 1 = 1 : 2 : 6 6 3 ∴ Time taken by A = 72 = 12 minutes 6 Correct Option: D
Ratio of the speed of A, B and
C = 6 : 3 : 1
⇒ Ratio of the time taken= 1 : 1 : 1 = 1 : 2 : 6 6 3 ∴ Time taken by A = 72 = 12 minutes 6
