Một hộp đựng 12 bóng đèn, trong đó có 5 bóng đèn bị hư. Lấy ngẫu nhiên từ hộp ra 2 bóng đèn. Gọi X là số bóng đèn bị hư lấy được trong 2 bóng đèn lấy ra. Tìm E(X); D(X) và mod X.

Ray ce is the angle bisector of zacd, which statement about the figure must be true? mzecd-mzecb mzace « 4mzacd zace - zdcb zecd zacd save and exit

The cross-sectional areas of a right triangular prism and a right cylinder are congruent. the right triangular prism has a height of 6 units, and the right cylinder has a height of 6 units. which conclusion can be made from the given information? the volume of the triangular prism is half the volume of the cylinder. the volume of the triangular prism is twice the volume of the cylinder. the volume of the triangular prism is equal to the volume of the cylinder. the volume of the triangular prism is not equal to the volume of the cylinder.

Suppose the equation ||x-a|-b|=2008 has 3 distinct real roots and a not =0. find the value of b.