A wise man once said, "500 reduced by 3 times my age is 200." What is his age?

The answer is:  " 100 " .
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Explanation:
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Let "x" represent the numerical value of [the man's age].

  500 - 3x = 200 ;  Solve for "x" ; 

 Subtract "500" from each side of the equation:

  500 - 3x - 500 = 200 - 500 ; 

to get:

   - 3x = -300 ; 

Now, divide each side of the equation by "-3" ; to isolate "x" on one side of the equation; & to solve for "x" ; 

   - 3x / -3 = -300 / -3 ; 

         x = 100 . 
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The answer is:  " 100 " .
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