SOLUTION: A boat crew rowed 13.5 miles with the current in 1.5 hours. The return trip against the current covered the same distance but took 4.5 hours. Find crews rate in still water and rat
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Question 915210: A boat crew rowed 13.5 miles with the current in 1.5 hours. The return trip against the current covered the same distance but took 4.5 hours. Find crews rate in still water and rate of current. Answer by mananth(16946) (Show Source):
You can put this solution on YOUR website! Boat speed speed =x mph
current speed =y mph
against current 4.5 hours
with current 1.5 hours
Distance against 13.5 miles distance with 13.5 miles
t=d/r against current -
13.50 / ( x - y )= 4.50
4.50 ( x - y ) = 1.50
4.50 x - 4.50 y = 13.50 ....................1
13.50 / ( x + y )= 1.50
1.50 ( x + y ) = 13.50
1.50 x + 1.50 y = 13.50 ...............2
Multiply (1) by 1.50
Multiply (2) by 4.50
we get
6.75 x + -6.75 y = 20.25
6.75 x + 6.75 y = 60.75
13.50 x = 81.00
/ 13.50
x = 6.00 mph
plug value of x in (1) y
4.50 x -4.50 y = 13.50
27.00 -4.50 -27.00 = 13.50
-4.50 y = 13.50
-4.50 y = -13.50 mph
y = 3.00
Boat speed speed 6.00 mph
current speed 3.00 mph
