SOLUTION: A river is flowing at a rate of 5 km/h. A boat travels 12 km upstream and 10 km downstream in a total of 5 hours. What is the speed of the boat in still water? A. 17.6 km/h C. 4

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Question 1186383: A river is flowing at a rate of 5 km/h. A boat travels 12 km upstream and 10 km
downstream in a total of 5 hours. What is the speed of the boat in still water?
A. 17.6 km/h
C. 43.5 km/h
B. 27.6 km/h
D. 54.6 km/h
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
b, boat speed
5, river speed 
          SPEEDS     TIME             DISTANCE

UP         b-5       12/(b-5)           12

DOWN       b+5       10/(b+5)           10

TOTAL                 5

Make the time sum equation.
12%2F%28b-5%29%2B10%2F%28b%2B5%29=5
Simplify and solve.