A) 672750
B) 68250
C) 2960100
Step-by-step explanationA) We have 26 letters from which to choose 4, and 10 digits from which to choose 2:

B) We have 26 letters from which to choose 2, and 10 digits from which to choose 4:

C) We have 26 letters from which to choose 5, and 10 digits from which to choose 2:
