(b) The probability that the 5th person is the first person not in favour is given by the geometric distribution formula:

\((0.8)^4 \times (0.2) = 0.08192\)

This is because the first four people are in favour (probability 0.8 each), and the 5th person is not in favour (probability 0.2).

(c) The probability that the 7th person is the second person not in favour is calculated using the negative binomial distribution:

\((0.8)^5 \times (0.2)^2 \times 6 = 0.0786\)

This accounts for 5 people in favour, 2 not in favour, and the combination factor of choosing which two out of seven are not in favour.