Answer:
a. 1,215,454 ways
b. 29,170,800 ways
Explanation:
a. If the four cakes are identical, order does not matter, and the total number of ways to award the cakes is given by a combination, C(75,4):

b. If the four cakes are different, order does matter, and the total number of ways to award the cakes is given by a permutation, P(75,4):
