Trong một thùng có chứa 3 bi đỏ, 4 bi đen. Lấy ngẫu nhiên từng viên cho đến khi lấy được bi đỏ thì dừng. Gọi X là số viên bi cần lấy. Tìm quy luật ppxs cho X.

An assembly consists of two mechanical components. suppose that the probabilities that the first and second components meet specifications are 0.87 and 0.84. assume that the components are independent. determine the probability mass function of the number of components in the assembly that meet specifications. x

Pls the last one and it has to be like number 6

Spencer has 1/3 pound of nuts he divides them equally into 4 bags what fraction of a pound of nuts is in each bag