Andy C. answered • 11/05/17

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168 = (r-s)*14

168 = (r+s)*12

14(r - s) = 12(r+s)

14r - 14s = 12r + 12s

14r - 14s - 12r - 12s = 0

2r - 26s = 0

2r = 26s

r = 13s

168 = (13s-s)14

168 = 12s*14

168 = 168s

s=1

r=13(1) = 13

CHECK:

Upstream: (13-1)*14 = 12*14 = 168

DOwnstream (13+1)*12 = 14*12 = 168

The speed of the boat is 13 mph

the spped of the current is 1 mph