If 2x + 13x = 5 , then the value of 5x6x^2 + 20x + 1 is?

Answer: Option D

$$\begin{array}{rl}& 2x+\frac{1}{3x}=5\\ & 6x^2\text{ + 1 = 15x}......\text{(i)}\\ & \text{Now,}\frac{5x}{6x^2+20x+1}\\ & =\frac{5x}{6x^2+1+20x}\\ & \left[\text{From equation (i)}\right]\\ & =\frac{5x}{15x+20x}\\ & =\frac{5x}{35x}\\ & =\frac{1}{7}\end{array}$$