A.1 Arranging Subset

In how many ways can we arrange 2 letters from A, B, C?

  • AB
  • BA
  • AC
  • CA
  • BC
  • CB
  • Again 6 ways, but we get it using \(^3P_2 = \frac{3!}{(3-2)!}=\frac {6}{1!}=6\)