Question

x, y, z are 3 non zero positive integers such that x+y+z = 8
and xy+yz+zx = 20, then minimum possible value of x*y^2*z^2 will be

Answer 1

(x+y+z)² = x² + y² + z² + 2 (xy + yz + zx)
            x² + y² + z² = 8² - 2 * 20 = 24