SOLUTION: A motorboat has a four-hour supply of gasoline. How far from the marina can it travel if the rate going out against the current is 20mi/h and the rate the rate coming back with th
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Question 134362This question is from textbook algebra
: A motorboat has a four-hour supply of gasoline. How far from the marina can it travel if the rate going out against the current is 20mi/h and the rate the rate coming back with the current is 30mi/h? This question is from textbook algebra
You can put this solution on YOUR website! rt=d r=rate t=time d=distance
Let a=time going against the current, w=time going with the current
The distance up the river equals the distance down.
M) a+w=4
N) 20a=30w
.
M) 30a+30w=120 multiply each side by 30.
N) 20a-30w=0
----------------add
==>50a=120
.
a=120/50=12/5 hrs
w=4- 12/5 =8/5 hrs
.
20*12/5=48 mi Ans.
.
Check:
30*8/5=48 mi
.
Ed
