numere prime
2, 3, 5, 7, 11, 13
avem 6 numere prime
p = 6×100/15 = 600/15 = 40%
cazul 1
p + p + p = 52
intre cele 15 cartonase avem 7 cartonase cu numere pare
2, 4, 6, .. 12, 14
mai adaugam 3
total cartonase = 18
total cartonase pare = 10
p = 10×100/18 = 1000/18 = 55,(5) %
cazul 2
i + i + p = 52
adaugam un cartonas par = 8
total cartonase = 18
total cartonase pare = 8
p = 8×100/18 = 800/18 = 44,(4) %