A car covered a distance of 180 km at a uniform speed. If the speed is reduced by 5 km/h, the journey takes 1 hour longer. Find the original speed. MCQ with Answer and Explanation
A car covered a distance of 180 km at a uniform speed. If the speed is reduced by 5 km/h, the journey takes 1 hour longer. Find the original speed.
A. 25 km/h
B. 35 km/h
C. 30 km/h
D. 40 km/h
Answer: Option C
Solution (By JKSSB Mock Tests)
Let original speed be s. 180 / (s - 5) - 180 / s = 1 => 180(5) = s(s - 5) => 900 = s(s - 5). Solving s^2 - 5s - 900 = 0 gives (s - 30)(s + 25) = 0. Since speed is positive, s = 30 km/h.
A distance of 600 km is covered by a passenger train in 12 hours. If the speed of an express train is 20 km/h more than that of the passenger train, how much less time will the express train take to cover the same distance?
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