A boat can row 10 km/h in still water and the speed of the current is 2 km/h. Find the time taken to row 24 km upstream. MCQ with Answer and Explanation

Explanation:
Let speed of current be c km/h. Downstream speed = 10 + c, Upstream speed = 10 - c. Given: 2 * (10 - c) = 10 + c => 20 - 2c = 10 + c => 3c = 10 => c = 10/3 = 3.33 km/h.

Explanation:
Downstream speed = 24 / 2 = 12 km/h. Upstream speed = 12 / 2 = 6 km/h. Speed in still water = (12 + 6) / 2 = 9 km/h.

Explanation:
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.