// Reduce a fraction by finding the Greatest Common Divisor and dividing by it.

function reduce(numerator,denominator){

  var gcd = function gcd(a,b){

    return b ? gcd(b, a%b) : a;

  };

  gcd = gcd(numerator,denominator);

  return [numerator/gcd, denominator/gcd];

}



reduce(2,4);

// [1,2]



reduce(13427,3413358);

// [463,117702]