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.
But mostly Generation Y is a made-up generation when it became obvious that young kids didn't really fit with the cool Generation X aesthetic but not enough of them had been born to make a new generation designation. NOTE: Generation Y is a fake, made-up thing. Do not worry about it. Millennials.