c) There are 5 even digits (0, 2, 4, 6, 8)
First digit = 5 possibilities
Second digit = 4 possibilities
Third digit = 8 possibilities
First letter = 26 possibilities
Second letter = 25 possibilities
Third letter = 24 possibilities
Total number of possibilities = 5 x 4 x 8 x 26 x 25 x 24 = ...
d) First digit = 9 possibilities
Second digit = 9 possibilities
Third digit = 8 possibilities
First letter = 26 possibilities
Second letter = 25 possibilities
Third letter = 24 possibilities
Total number of possibilities = 9 x 9 x 8 x 26 x 25 x 24 = ...