a tugboat goes 120 miles upstream is 15hours. the return trip downstream takes 5 hours.find the speed of the tugboat without a current and the speed of the current.

Question

anonymous · Answer

Not 100% sure, ask @jim_thompson5910

jim_thompson5910 · Answer

Hint: 

Let x = speed of the boat (without the current) and c = speed of the current

Upstream equation:

d = rt

120 = (x-c)*15

--------------------

Downstream equation:

d = rt

120 = (x+c)*5

jim_thompson5910 · Answer

You have 2 equations with 2 unknowns, which you can solve for both x and c.

anonymous · Answer

the speed of the tugboat is blank mph, and the speed of the current is blank mph.. what is both speed

jim_thompson5910 · Answer

120 = (x-c)*15

120/15 = x-c

8 = x-c

x = 8 + c

-------------------------


120 = (x+c)*5

120 = (8+c+c)*5

120 = (8+2c)*5

120 = 40 + 10c

Now solve for c