<h3>
Answer: 14 km per hour</h3>
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Work Shown:
x = rowing speed when there is no current
c = speed of the current
speeds are in km per hour
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Going downstream, i.e. with the current:
x+c = faster speed since the current is pushing you
distance = rate*time
d = r*t
40 = (x+c)*2
x+c = 40/2
x+c = 20
c = 20-x
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Going upstream, i.e. against the current:
x-c = slower speed since the current is working against you
d = r*t
16 = (x-c)*2
16 = 2x-2c
2x-2c = 16
2(x-c) = 16
x-c = 16/2
x-c = 8
x-(20-x) = 8 ... plug in c = 20-x
x-20+x = 8
2x-20 = 8
2x = 8+20
2x = 28
x = 28/2
x = 14 km per hour is the rowing speed when there is no current
Side note: the speed of the current is c = 20-x = 20-14 = 6 km per hour.
