If the permutation of  a,b,c,d,e taken all together be written down in alphabetical order as in dictionary and numbered, then the rank of the permutation debac is:

How many 3 letter words with or without meaning can be formed out of the letters of the word SMOKE when repetition of words is allowed?

The number of ways in which three boys can be seated on five chairs?

 How many permutations of 3 different letters are there, chosen from the four letters of the alphabet?

How many permutations of 4 different letters are there, chosen from the twenty six letters of the alphabet?

Complete:

The exponent of 3 in 100 !, is _________.

Complete:

The number of times the digit 3 will be written when listing the integers from 1 to 1000 is ___________.

 How many permutations of 3 different digits are there, chosen from the ten digits 0 to 9 inclusive?

How many permutations of 3 different digits are there, chosen from the ten digits 0 to 5 inclusive?

A special type of password consists of four different letters of the alphabet, where each letter is used only once. How many different possible passwords are there?