The probability of getting a 4 again means is given by the product of the probabilities to obtain 4 twice (because in this case we have independent events)
(a) P(4I4) = P(4)*P(4) = (1/6)(1/6) = 1/36
(b) P(1l4) = P(1)*P(4) = (1/6)(1/6) = 1/36
In the previous calculations we have considered that the probability for getting any number is the same and it is 1/6.