Answer:
boat: 35 mph; current: 7 mph
Explanation:
Let b and c represent the speeds of the boat and the current in miles per hour. Using the relationship ...
distance/speed = time
we can write equations for the time going downstream and that going upstream.
14/(b+c) = 1/3 . . . . speeds add going downstream
14/(b-c) = 1/2 . . . . . current subtracts from boat speed going upstream
These can be rearranged to the two linear equations ...
b + c = 42
b - c = 28
Adding the two equations gives ...
2b = 70
b = 35 . . . . . . divide by 2
From the first equation, ...
c = 42 -b = 42 -35 = 7
The speed of the boat in calm water is 35 mph; the speed of the current is 7 mph.