Question

how many 4 letter passwords can be formed from the letters in the word panicky if each letter has to be distinct what if letters are allowed to be repeated

Answer 1

The word PANICKY has 7 letters. The password chosen must have 4 letters total.

If each letter has to be distinct, meaning that the letters all have to be different, then there are 7*6*5*4 = 840 ways.

If the letters are allowed to be repeated then there are 7*7*7*7 = 7^4 = 2,401 ways.