SOLUTION: A boat travels 30 miles up the river in the same amount of time it takes to travel 46 miles down the same river. If the current is 4 miles per hour, what is the speed of the boat i
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Question 1057577: A boat travels 30 miles up the river in the same amount of time it takes to travel 46 miles down the same river. If the current is 4 miles per hour, what is the speed of the boat in still water? Answer by ikleyn(52776) (Show Source):
You can put this solution on YOUR website! .
A boat travels 30 miles up the river in the same amount of time it takes to travel 46 miles down the same river.
If the current is 4 miles per hour, what is the speed of the boat in still water?
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The governing equation is
= ("time" equation; u is the boat speed in still water)
Cross-multiply:
30*(u+4) = 46(u-4),
30u + 120 = 46u - 184,
120 + 184 = 46u - 30u,
304 = 16u ---> u = = 19.
Answer. The boat speed in still water is 19 mph.
