A boatman rows 30 km downstream and 18 km upstream, taking 3 hours for each leg of the journey. Find the speed of the boat in still water. MCQ with Answer and Explanation

Explanation:
Time to cross the platform distance alone = 14 - 6 = 8 seconds. Speed of train = 160 / 8 = 20 m/s. Length of train = Speed * Time to pass observer = 20 * 6 = 120 meters.

Explanation:
Let original speed be s. 24 / (s - 2) - 24 / s = 1 => 24(2) = s(s - 2) => 48 = s(s - 2). Solving s^2 - 2s - 48 = 0 yields (s - 8)(s + 6) = 0. Since speed must be positive, s = 8 km/h.

Explanation:
Let each third segment distance be 40 km. Total sector distance = 120 km. Total time = 40/20 + 40/40 + 40/40 = 2 + 1 + 1 = 4 hours. Average speed across route = 120 / 4 = 30 km/h.