1. Numerele prime intre 1 si 30 sunt:(2, 3, 5, 7,11,13,17, 19, 23, 29)
P=10/30=1/3
Numerele compuse sunt(4, 5, 8, 9, 10, 12, 14, 15, 16, 18, 20, 21, 22, 24, 25, 26, 27, 28)
P=18/30=6/10=3/5
2. a) P=3/6=1/2 (1, 3, 5)=nr. i,pare
b)P=2/6=1/3 (3,6)=nr. div. cu 3
c)P=1/6 (5)=singurul care se div. cu 5
3. A=(1, 2, 3, 4) 2x-5=1=>x=3
P=1/4