If the fourth term in the binomial expansion of ${\left( {{2 \over x} + {x^{{{\log }_8}x}}} \right)^6}$ (x > 0) is 20 × 87, then a value of x is :

Question

If the fourth term in the binomial expansion of ${\left( {{2 \over x} + {x^{{{\log }_8}x}}} \right)^6}$ (x > 0) is 20 × 8⁷, then a value of x is :