.
How many four-letter "words" can be made from 6 letters "AEBWDP" if
repetition of letters is allowed
= 1296 ways;
6 opportunities in each of 4 positions.
repetition of letters is not allowed
= 360 ways.
6, 5, 4 and 3 opportunities in the 1-st, 2-nd, 3-rd and 4-th position, respectively.
Solved.