Discuss Forum
1. A motorcyclist completes a certain journey in 5 hours. He covers one-third distance at 60 km/hour and the rest 80 km/hour. The length of the journey is-
- A. 240 km
- B. 240 km
- C. 240 km
- D. 240 km
Answer: Option D
Explanation:
Time taken by the the motorcyclist = 5 hours
Speed while covering 1/3rd distance of the distance = 60 km/hr
Speed while covering 2/3rd of the distance = 80 km/h
Formula Used:
Time = Distance/Speed
Calculation:
Let the length of the entire journey = 3a
As per the question;
(3a × 1/3)/60 + (3a × 2/3)/80 = 5
বা,a/60 + 2a/80 = 5
বা, (4a + 6a)/240 = 5
বা, 10a/240 = 5
বা, a = 120
বা, 3a = 3 × 120 = 360.
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