Question 1133091
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Let the rate of the current be "x" miles per hour.

Then the speed of the jet ski upstream is (60-x) mph.


Moving  {{{1/4}}} of an hour upstream, it covered the distance  {{{(1/4)*(60-x)}}}  miles.


Then it moved downstream with the speed equal to the rate of the current x mph during  {{{3}}}{{{3/4}}} hours = {{{15/4}}} hours 

and covered the distance  {{{(15/4)*x}}} downstream.


We are given that  


    {{{(15/4)*x}}} = {{{(1/4)*(60-x)}}} + 2.


It is your basic equation.

To solve it, multiply first both sides by 4; then simplify step by step:


    15x = 60-x + 8

    15x + x = 60 + 8

    16x = 68  ==============>  x = {{{68/16}}} = {{{17/4}}}.


<U>ANSWER</U>.  The rate of the current is  {{{17/4}}} = {{{4}}}{{{1/4}}} miles per hour.
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