Answer:
Alvin traveled 150 miles downstream and 150 miles upstream, for a total distance on the river of 300 miles.
Step-by-step explanation:
Let d represent the distance Alvin traveled in one direction on the river. Then going downstream that distance took ...
... time = distance/speed
... time downstream = d/25
and the time going upstream that same distance to his point of origin took ...
... time upstream = d/15
The total of these times is 16 hours, so we have ...
... 16 = d/25 + d/15
Multiplying by 75 gives ...
... 1200 = 3d +5d = 8d
... 1200/8 = d = 150
Alving spent 6 hours going 150 miles downstream and 10 hours going 150 miles upstream. His total river distance was 300 miles. (We cannot tell which of these numbers will be considered to be the answer to the question.)
