Question 1170220
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Let x be the unknown value under the question.


Then from the condition you have this equation


    {{{15/(x-2)}}} - {{{15/x}}} = 2   days.


You can solve it formally, reducing the equation to the standard quadratic form.


But the solution is seen immediately  x= 5  meters.


<U>CHECK</U>.  {{{15/(5-2)}}} - {{{15/5}}} = {{{15/3}}} - {{{15/5}}} = 5 - 3 - 2 days.   ! Correct !
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Solved &nbsp;&nbsp;// &nbsp;&nbsp;mentally.