SOLUTION: A boat travels 36 miles with current in 2 hours and 42 miles agents the current in 3 hours find the speed of boat in still water

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Question 1104699: A boat travels 36 miles with current in 2 hours and 42 miles agents the current in 3 hours find the speed of boat in still water
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +c+ = the rate of the current in mi/hr
Let +s+ = the speed of the boat in still water
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Traveling with the current:
(1) +36+=+%28+s+%2B+c+%29%2A2+
Traveling against the current:
(2) +42+=+%28+s+-+c+%29%2A3+
------------------------------
(1) +2s+%2B+2c+=+36+
(1) +s+%2B+c+=+18+
and
(2) +3s+-+3c+=+42+
(2) +s+-+c+=+14+
--------------------------
Add (1) and (2)
+2s+=+32+
+s+=+16+
The speed of the boat in still water is 16 mi/hr
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check:
(1) +s+%2B+c+=+18+
(1) +16+%2B+c+=+18+
(1) +c+=+2+
and
(2) +s+-+c+=+14+
(2) +16+-+c+=+14+
(2) +c+=+2+
OK