Find the number of bijective functions between two sets A and B, where A = {a, b, c, d, e} and B = {p, q, r, s, t}

The number of bijective functions between A and B is 5! = 120, because there are 5 elements in each set. This means that there are 120 different functions that can be defined that are bijective, i.e. every element in set A maps to exactly one element in set B, and every element in set B also maps to exactly one element in set A.