## Realated Questions

Find the total number of ways in which a black square and a white square can be selected from a chessboard such that both the squares lie either in the same row or in the same column.

P is a point outside the circle with centre O. If a straight line drawn through P intersects the circle at points A and B such that and 90

^{0 }< ∠AOB < 120^{0}, which of the following could be the radius (in cm) of the circle?In the figure above, PQRS is a cyclic quadrilateral, where PQ = p cm, QR = q cm, RS = r cm and PS = s cm. If (PQ) (QR) = 3(PS) (RS) and ∠PQR =120

^{0}, then s =