A car covers a distance of 180 km in 3 hours. What should be the increase in its speed to cover the same distance in 2 hours? MCQ with Answer and Explanation

Explanation:
Speed = 100 / 5 = 20 m/s. In km/h = 20 * (18/5) = 72 km/h.

Explanation:
Upstream speed = 18 - 4 = 14 km/h. Distance covered = Upstream speed * Time = 14 * 5 = 70 km.

Explanation:
Let original speed be s. 450/s - 450/(s+5) = 1 => 450(s + 5 - s) = s(s + 5) => 2250 = s(s + 5). Solving s^2 + 5s - 2250 = 0 gives (s - 45)(s + 50) = 0. Since speed is positive, s = 45 km/h.