When two events (call them A and B) are Mutually Exclusive it is impossible for them to happen together: P(A and B) = 0. The probability of A and B together equals 0 (impossible).
Generation Z. Generation Z (also known as The Founders, Post-Millennials, the iGeneration, Plurals or the Homeland Generation) is the demographic cohort after the Millennials.
Generation Y refers to the population group in the US born from somewhere around 1976 to around 2000. They are sometimes called echo boomers because some of them are the children of baby boomers. On the other hand, some Generation Y children, especially those born in the late 1980s or afterwards, may be the grandchildren of baby boomers. Other names for this group are the Millennials, the Internet Generation, and the abbreviated Gen Y or Gen Yers.