Based on past experience, it is assumed that the number of flaws per foot in rolls of grade 2 wallpaper follows a Poisson distribution with a mean of 1 flaw per 5 feet of wallpaper (i.e., 0.2 flaw per foot). What is the probability that in a
a. 1-foot roll, there will be at least 2 flaws?
b. 12-foot roll, there will be at least 1 flaw?
c. 50-foot roll, there will be more than or equal to 5 flaws and fewer than or equal to 15 flaws?