GATE Electrical 2023 | Question: 35

Question

The expected number of trials for first occurrence of a "head" in a biased coin is known to be $4.$ The probability of first occurrence of a "head" in the second trial is ____________(Round off to $3$ decimal places).

Answer 1

if probability of head is $p$ then expected no of trials to get a head =$\frac{1}{p}=4$

probability of head = $\frac{1}{4}$

probability of not head = $\frac{3}{4}$

first head in second trial, so not head and head=$\frac{3}{4}\frac{1}{4}=0.1875$