A code signal uses digit-letter-digit combinations but 0 and 1 are not used for either digits or letters. How many code signals are possible?
Since 0 and 1 are not used, total usable digits = 8
Total usable letters = 26
If repetition is allowed, total number of code signals possible = 8x26x8 = 1664
If repetition is NOT allowed, total number of code signals possible = 8x26x7 = 1456
Total usable letters = 26
If repetition is allowed, total number of code signals possible = 8x26x8 = 1664
If repetition is NOT allowed, total number of code signals possible = 8x26x7 = 1456