( x + y + z ) / 3 =17
x + y + z = 3 · 17
x + y +z = 51
20 < x = prim < 28
atunci x = 23 ; 29
daca x = 23 23 + y + z = 51 ; y +z = 51 - 23
y + z = 28
med.aritm = ( y + z ) / 2 = 28 /2 = 14
daca x = 29 29 + y + z = 51 ; y + z = 51 - 29
y + z = 22
med. aritm . =( y +z ) /2 = 22 /2 = 11