what does this mathmatical term mean.....?

Question

i took a practice exam and came across something im not familier with.....what does (3)P(3) mean? I mean i kno the answer is 3! but i wanna kno how to get that number

the numbers in the parenthensis are subnumbers.......i dont kno how to show them w/o using HTML

Answer 1

nPr = n(n-1)(n-2)...[n-(r-1)]

meaning the permutation of n objects taken r at a time

nPn = n!