A car traveling at a uniform speed covers 300 km. If the speed had been 10 km/h more, it would have taken 1 hour less. Find the initial speed. MCQ with Answer and Explanation
A car traveling at a uniform speed covers 300 km. If the speed had been 10 km/h more, it would have taken 1 hour less. Find the initial speed.
A. 45 km/h
B. 50 km/h
C. 60 km/h
D. 55 km/h
Answer: Option B
Solution (By JKSSB Mock Tests)
Let original speed be s. 300 / s - 300 / (s + 10) = 1 => 300(10) = s(s + 10) => 3000 = s(s + 10). Solving s^2 + 10s - 3000 = 0 gives (s - 50)(s + 60) = 0. Since speed is positive, s = 50 km/h.
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