Problem in disription

Question

Julie and Eric row their boat (at a constant speed) 24 miles downstream for 4 hours, helped by the current. Rowing at the same rate, the trip back against the current takes 6 hours. Find the rate of the current.

Answer 1

rdistance = rate*time ... d = rt

 

Let r = rowing speed

Let c = current speed

 

downstream:

24 = (r+c)4

r + c = 6

 

Upstream:

24 = (r-c)6

r -c = 4

 

we have two equations:

r + c = 6

r - c = 4  add the equations

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2r = 10

r = 5 mph rowing speed

 

plugging into original equations

r + c = 6

c = 1

 

The current speed is 1 mile per hour