1. (p+q+r)!/(p! × q ! × r!)
  2. (p,q,r)=(3,3,0), (p,q,r)=(2,2,1), (p,q,r)=(1,1,2) ou (p,q,r)=(0,0,3).
  3. 6!/(3! × 3!)+5!/(2! × 2!)+ 4!/2!+1
  4. 111