How fast can Jim row in still water ? What is the speed of current ?

Question

It takes Jim 3 hours to row 12 miles with the current downstream and it takes him 6 hours to row the same distance against the current upstream.

Answer 1

boat speed in still water = 3mph

current speed = 1 mph

d=rt distance = rate of speed times time

12 = (3+1)(3) = 4x3 for downstream

12 = (3-1)(6) = 2x6 for upstream

12 = (b-c)(6) = (b+c)(3) b= boat speed in still water, c= current speed

6b-6c = 3b+3c

2b-2c = b+c

b = 3c. boat speed is 3 times the current speed

12 = (b+c)(3) = (3c+c)(3)

4 = 4c

c = 1 mph

b =3(1) = 3mph