Question

Let the probability of getting head for a biased coin be $\frac{1}{4}$ . It is tossed repeatedly until a head appears. Let N be the number of tosses required. If the probability that the equation $64x² + 5Nx + 1 = 0$ has no real root is $\frac{p}{q}$ , where p and q are co-prime, then q – p is equal to _______.

Answer 1

The Answer is 27