How many 4-permutations of the positive integers not exceeding 100 contain three consecutive integers k, k +

Question:

How many 4-permutations of the positive integers not exceeding 100 contain three consecutive integers k, k + 1, k + 2, in the correct order
a) Where these consecutive integers can perhaps be separated by other integers in the permutation?
b) Where they are in consecutive positions in the permutation?