SOLUTION: An athlete plans to row upstream a distance of 6 km and then return to his starting point downstream in a total time of 4 hours. If the speed of the current is 2 km/h, what is the

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Question 1170886: An athlete plans to row upstream a distance of 6 km and then return to his starting
point downstream in a total time of 4 hours. If the speed of the current is 2 km/h, what is the
rowing speed of the athlete in still water?

Answer by ikleyn(52812)   (Show Source): You can put this solution on YOUR website!
.
An athlete rows upstream a distance of 6 km and then returns to his starting
point downstream in a total time of 4 hours. If the speed of the current is 2 km/h, what is the
rowing speed of the athlete in still water?
~~~~~~~~~~~~~


            Notice that in your formulation  I  EXCLUDED  the  UNNECESSARY  words,  to which  THERE  IS  NO  PLACE
            in the  TRUE  Math  problem formulation.   They are  REALLY  EXCESSIVE . . .


Let x be the athlete' speed in still water.


Then his (or her) speed downstream is (x+2) miles per hour and the time rowing downstream is    hours;

while         the speed   upstream is (x-2) miles per hour and the time rowing   upstream is    hours.


The total time equation is


     +  = 4 hours.


If you want to solve it formally, you should reduce it to a quadratic equation and then
solve it using the quadratic formula or by factoring.


Fortunately, the solution/(the answer) is clearly seen right from the equation: it is  x= 4 miles per hour.    ANSWER


Indeed,   +  =  +  = 1 + 3 = 4 hours,  so my answer is correct.

Solved.

-------------

It is a typical and standard Upstream and Downstream round trip word problem.

You can find many similar fully solved problems on upstream and downstream round trips with detailed solutions in lessons
    - Wind and Current problems solvable by quadratic equations
in this site, where you will find other similar solved problems with detailed explanations.

Read it attentively and learn how to solve this type of problems once and for all.

Also,  you have this free of charge online textbook in ALGEBRA-I in this site
    - ALGEBRA-I - YOUR ONLINE TEXTBOOK.

The referred lesson is the part of this textbook under the section "Word problems",  the topic "Travel and Distance problems".


Save the link to this online textbook together with its description

Free of charge online textbook in ALGEBRA-I
https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson

to your archive and use it when it is needed.



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