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 8km

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 8km per​ hr, what was her boat speed in still​ water?

Answer 1

15 minutes upstream= 1/4 hour

5 minutes downstream = 1/12 hour

current speed = 8 km/hr

d=rt= (c+b)t, c= current speed, b= boat speed in still water

d= 2 km

b= 16 km/hr= speed of the boat in still water

(16+8)(1/12)=24/12= 2 km

(16-8)(1/4)= 8/4 = 2 km

same distance each way