Răspuns:
A de 10 luate câte 8 = [tex]\frac{10!}{(10-8)!} =\frac{10!}{2!} =90[/tex]
Permutari de 3 = 3! = 1 x 2 x 3 = 6
A de 5 luate cate 3 = 60
==> 90-6 / 60 ==>84/60=42/ 30 = 14 / 10 = 7/ 5
