Last problem I need help with. A tugboat goes 180 miles upsteam in 15 hours. The return trip downstream takes 5 hours. Find the speed of the tugboat without a current and the speed of the current.

Question

lgbasallote · Answer

upstream speed = speed of boat - speed of current

downstream speed = speed of boat + speed of current

upstream speed is $$\frac{180}{15} \implies 12 mph$$
downstream speed is $$\frac{180}{5} \implies 36 mph$$

so we use the formula i gave

upstream = b - c
downstream = b +c

where b = speed of boat
c = speed of current

12 = b - c
36 = b +c
=======
48 = 2b <---add the two equations

now solve for b

2b = 48
b = 48/2
b = 24 mph

since downstream speed is 36...

dwnstream = b +c
36 = 12 + c
36 - 12 = c
24 = c

lgbasallote · Answer

uhh i  made a mistake..

downstream = b + c

36 = 24 + c
36 - 24 = c
12 = c

lgbasallote · Answer

did you get that @ldepallo

anonymous · Answer

ok

anonymous · Answer

so which one is the speed of the tugboat and which one is the current?

lgbasallote · Answer

look at my solution. i mentioned it *if* you read the solution

anonymous · Answer

ok