i need help on B and D please

a (Required) According to the Earth Policy Institute (July 2013), 60% of the world's solar energy cells are manufactured in China. Consider a random sample of 5 solar energy cells, and let X represent the number in the sample that are manufactured in China. The probability distribution for X is given by the formula P(X = 1) = 5!(0.6)"(0.4)52 c!(5 c)! (a) Explain why X is a discrete random variable. a (b) Find P(X = x) for X = 0,1,2,3,4,5. (C) Show that the properties for a discrete probability distribution are satisfied. 1 I (d) Find the probability that at least 4 of the 5 solar energy cells in the sample are manufactured in China