Question

Jane took 15 min to drive her boat upstream to​ water-ski at her favorite spot. Coming back later in the​ day, at the same boat​ speed, took her 5 min. If the current in that part of the river is 4 km per​ hr, what was her boat speed in still​ water

Answer 1

The speed of the boat in still water = 8 Km/hr

Explanation:

Let the speed of the boat be x

According to question

(x-4)15 = (x+4)5

3x-12 = x+4

⇒x = 8 km/hr