A motorboat travels 258mi in 6 hours going upstream. It travels 330mi going downstream in same amount of time. What's the rate of the boat in still w

Question

Algebra - A motorboat travels
258mi
in
6
hours going upstream. It travels
330mi
going downstream in the same amount of time. What is the rate of the boat in still water and what is the rate of the current? 

Answer 1

B = the speed of the boat in still water.

S = the speed of the stream

 

Relative to the bank, the speed upstream is B-S.

The speed downstream is B+S.

 

Use the equation for distance.

Rate * Time = Distance

Upstream

(B-S)6 = 258

(B+S)6 = 330

 

Simplify first:

B-S = 43

B+S = 55

Solve by elimination.  Add the two equations.

2B = 98

B = 49 mi/hr

Substitute this into either equation and solve for S.

B+S = 55

49+S = 55

S = 6 mi/hr