A child has placed 9 blocks in a row.. The blocks are of two different types, two of type A and 7 of type B. The blocks of type A are supposed to be placed in the first 2 spots but since they are randomly placed some type B blocks may preceed them. Let X be the number of type B blocks that preceed the first type A block. Find the probability function ax) of X. You may use symbols ()+*/" and preview your formula using they symbol | m) = .a for x=0,1,.. 7 b. What is the expected value of X? Number c. What is the variance of X? Number