A family has 2 children. Find the probability that both are boys, if it is known that
(i) At least one of the children is a boy
(ii) The elder child is a boy.Find the points on the line at a distance of 5 units from the point P (1, 3, 3).
Find the distance of the point p(6,5,9) From the plane determined by the points A(3,-1,2 ), B(5,2,4) and C (-1,-1,6).