Question

Trei numere au suma 80. Media aritmetica a primelor doua numere este12, iar media aritmetica a ultimelor doua numere este 36. Aflati numerele

Answer 1

$a+b+c=80$
$M_{aritmetica}=(a+b):2=12$⇒$a+b=2*12$⇒$a+b=24$⇒$a=24-b$
$M_{aritmetica} = (b+c):2=36$⇒$b+c=2*36$⇒$b+c=72$⇒
$c=72-b$
$a+b+c=80$⇒$24-b+b+72-b=80$$96-b=80$⇒$96-80=b$⇒$b=16$
$a=24-b$⇒$a=24-16$⇒$a=8$
$c=72-b$⇒$c=72-16$⇒$c=56$

Verificare
$a+b+c=16+8+56=80$