If a and b are the roots of the equation
x^{2} - kx + 16 = 0 and
satisfy a^{2} + b^{2} = 32, then the value of k is

If 8 and 2 are the roots of x^{2}
+ax+c = 0 and 3, 3 are the roots of x^{2} +dx+b = 0, then the roots

If a and b are the real roots of the
equation x^{2} -
kx + c = 0, then the distance between the points (a, 0) and (b, 0) is