f+7=22
fiul=15 ani
t+7=46
tatal=39 ani
prin metoda incercarilor ar fi
f=14------------t=38
f=13------------t=37
f=12------------t=36
f=11------------t=35
f=10-----------t=34
f=9------------t=33
f=8-------------t=32
f=7-------------t=31
f=6------------t=30
deci in final avem 9 ani
