Let $p, q$ be roots of the equation $x^{2}-4x+A=0$ and $r$ and $s$ be the roots of the equation $x^{2}-20x+B=0$. If $p < q < r < s$ are in A.P., then $(A, B)$ is

Roots p, q are for x^2 - 4x + A = 0. Roots r, s are for x^2 - 20x + B = 0. p, q, r, s are in AP. Let common difference be d. p=a, q=a+d, r=a+2d, s=a+3d. Sum of roots p+q = 2a+d = 4. Sum of roots r+s = 2a+5d = 20. Subtracting: 4d = 16, so d = 4. 2a+4 = 4, so a = 0. Roots are 0, 4, 8, 12. A = p*q = 0*4 = 0. B = r*s = 8*12 = 96.