During the first part of a trip, a canoeist travels 57 miles at a certain speed. The canoeist travels 18 miles on the second part of the trip at a speed 5 mph slower. The total time for the trip is 5 hours.

What was the speed(mph) on each part of the trip?

Question

During the first part of a trip, a canoeist travels 57 miles at a certain speed. The canoeist travels 18 miles on the second part of the trip at a speed 5 mph slower. The total time for the trip is 5 hours. 

What was the speed(mph) on each part of the trip?

anonymous · Answer

$$velocity=\frac{distance}{time}$$
First we can find the average v for the whole travel.
v=(57+18)/5=75/5=15 mph

How can we use that ?

anonymous · Answer

your guess is as good as mines i have no clue and just need help on the answer i have been stuck on this problem for 30 min.

lgbasallote · Answer

the canoist travels 57 miles at a certain speed

let n be this speed

the time he traveled here is 57/n (because time = distance/speed)

the canoeist travels 18 miles at a speed 5 mph slower than befor

let n - 5 be his speed at this interval

the time he traveled here is 18/n-5

the total time is 5 hours therefore

$$\frac{57}{n} + \frac{18}{n-5} = 5$$
does that make sense?

anonymous · Answer

lol this is what i got using a similar question i asked earlier but i need to know now how to convert this into a decimal to determine the mph 

i got 3.44256
and 16.5574

lgbasallote · Answer

determine what into decimal?