A security code consists of three letters chosen from the 26 in the alphabet followed by two digits from 0-9.
How many possible codes are there if there is no restriction on the two digits, but the letters must be consecutive letters of the alphabet and must feature in alphabetical order (reverse not permitted)

Question

A security code consists of three letters chosen from the 26 in the alphabet followed by two digits from 0-9.
How many possible codes are there if there is no restriction on the two digits, but the letters must be consecutive letters of the alphabet and must feature in alphabetical order (reverse not permitted)

anonymous · Answer

24*100 assuming means like abc and not skip like abd i think

anonymous · Answer

umm, can you explain your response?

anonymous · Answer

for the letters, there are only 24 possible combinations as there must be 2 letters after the first so y and z wont work for the first character. then there are 10*10 possible digits for the numbers

anonymous · Answer

thanks mate, i worked it out graphically, but wanted a more mathematical idea of how to do it. Cheers

anonymous · Answer

24 im pretty sure...?

anonymous · Answer

Based on what you have mentioned that the letters have to be consecutive and in alphabetical order there can only be 24 combinations for the three letter portion of the passcode.  The last two digits have 10 possible combinations.

So your total combinations would be the product of these.

24* 10 * 10 or 2300 different combinations.

anonymous · Answer

@luke23 Yes, you are correct.  I miss counted. :)

anonymous · Answer

Ugh, 2400.  I'm still a dork.