(c) The probability of not getting a 3 on a single spin is \(\frac{3}{4}\). The probability of getting a 3 on the 6th spin is:

\(P(Y = 6) = \left( \frac{3}{4} \right)^5 \times \frac{1}{4} = 0.0593\)

(d) The probability of not getting a 3 in the first 4 spins is \(\left( \frac{3}{4} \right)^4\). Therefore, the probability of getting a 3 after more than 4 spins is:

\(P(Y > 4) = \left( \frac{3}{4} \right)^4 = \frac{81}{256} = 0.316\)

Alternatively, \(P(Y > 4) = 1 - P(Y \leq 4)\) where:

\(P(Y \leq 4) = \frac{1}{4} + \frac{3}{4} \times \frac{1}{4} + \left( \frac{3}{4} \right)^2 \times \frac{1}{4} + \left( \frac{3}{4} \right)^3 \times \frac{1}{4}\)

\(P(Y > 4) = 1 - \frac{175}{256} = \frac{81}{256} = 0.316\)