Speed, Time and Distance
- A farmer travelled a distance of 61 km in 9 hours. He travelled partly on foot at a speed of 4 km/hour and partly on bicycle at a speed of 9 km/hour. The distance travelled on foot is :
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Length of journey on foot = x km. (let).
∴ Length of journey on cycle = (61 – x ) km.
According to the question,Time = Distance Speed ∴ x + 61 − x = 9 4 9 ⇒ 9x + 244 − 4x = 9 36
⇒ 5x + 244 = 36 × 9 = 324
⇒ 5x = 324 – 244 = 80⇒ x = 80 = 16 km 5 Correct Option: B
Length of journey on foot = x km. (let).
∴ Length of journey on cycle = (61 – x ) km.
According to the question,Time = Distance Speed ∴ x + 61 − x = 9 4 9 ⇒ 9x + 244 − 4x = 9 36
⇒ 5x + 244 = 36 × 9 = 324
⇒ 5x = 324 – 244 = 80⇒ x = 80 = 16 km 5
- Ravi has a roadmap with a scale of 1.5 cm for 18 km. He drives on that road for 72 km. What would be his distance covered in that map?
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∵ 18 km ≡ 1.5 cm
∴ 1 km ≡ 1.5 cm 18 Correct Option: B
∵ 18 km ≡ 1.5 cm
∴ 1 km ≡ 1.5 cm 18
- A motor cycle gives an average of 45 km per litre. If the cost of petrol is Rs. 20 per litre, the amount required to complete a journey of 540 km is, (in Rupees)
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Consumption of petrol in covering 540 km
= 540 = 12 litres 45
∴ Required expenses
= Rs. (12 × 20)
= Rs. 240Correct Option: D
Consumption of petrol in covering 540 km
= 540 = 12 litres 45
∴ Required expenses
= Rs. (12 × 20)
= Rs. 240
- Due to inclement weather, an air plane reduced its speed by 300 km/hr, and reached the destination of 1200 km late by 2hrs. Then the schedule duration of the flight was
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Let the original speed of aeroplane be x kmph.
According to the question,1200 − 1200 = 2 x − 300 x ⇒ 1200 x − x + 300 = 2 x(x − 300) ⇒ x (x – 300) = 1200 × 300 2
⇒ x (x – 300) = 600 × 300
⇒ x (x – 300) = 600 (600 – 300)
⇒ x = 600 kmph.∴ Scheduled duration of flight = 1200 = 2 hours 600 Correct Option: C
Let the original speed of aeroplane be x kmph.
According to the question,1200 − 1200 = 2 x − 300 x ⇒ 1200 x − x + 300 = 2 x(x − 300) ⇒ x (x – 300) = 1200 × 300 2
⇒ x (x – 300) = 600 × 300
⇒ x (x – 300) = 600 (600 – 300)
⇒ x = 600 kmph.∴ Scheduled duration of flight = 1200 = 2 hours 600
- A man can cover a certain distance in 3 hours 36 minutes if he walks at the rate of 5 km/hr. If he covers the same distance on cycle at the rate of 24 km/hr, then the time taken by him in minutes is
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Distance covered in 3 hours 36 minutes
i.e. 3 36 hours 60 i.e. 3 3 hours 5 = 5 × 18 = 18 km. 5
∴ Time taken at 24 kmph.= 18 hour 24 = 18 × 60 minutes 24
= 45 minutesCorrect Option: B
Distance covered in 3 hours 36 minutes
i.e. 3 36 hours 60 i.e. 3 3 hours 5 = 5 × 18 = 18 km. 5
∴ Time taken at 24 kmph.= 18 hour 24 = 18 × 60 minutes 24
= 45 minutes