Consideram numerele a;b;c
Daca acestea sunt consecutive => b=a+1; c=a+2
Media aritmetica={a;a+1;a+2}=102
=> a+a+1+a+2/3=120
3a+3/3=120=>3a+3=102*3
3a+3=306|-3
3a=303|:3
a=101
=>a+1=102=>b=102
a+2=103=>c=103
a+b+c=101+102+103
a+b+c=306=> Dublul sumei: 306*2=612
/=linia de fractie, impartire
*=înmulțire
