A boat rowed upstream measures 12 km/h and downstream measures 20 km/h. Find the speed of the boat hull in still water. MCQ with Answer and Explanation

Explanation:
Let original speed be s. 360/s - 360/(s+15) = 2 => 180/s - 180/(s+15) = 1 => 180(15) = s(s+15) => 2700 = s(s+15). Solving s^2 + 15s - 2700 = 0 gives (s - 45)(s + 60) = 0. Since speed is positive, s = 45 km/h.

Explanation:
Speed of runner-up = 100 / 13 m/s. Distance covered by runner-up in 12 seconds = (100 / 13) * 12 = 1200 / 13 = 92.31 meters. Beat distance = 100 - 92.31 = 7.69 meters.

Explanation:
Time = 2 minutes = 120 seconds. Speed = 600 / 120 = 5 m/s. In km/h = 5 * (18/5) = 18 km/h.