The following data were obtained from a survey of college students. The variable X represents the number of non-assigned books read during the past six months.
x 0 1 2 3 4 5
P (X=x) 0.20 0.25 0.20 0.15 0.10 0.10
Find P( X 5)
A. 0.10
B. 0.20
C. 0.90
D. 1.00