Pleas help me with the following practice questions so that I can better understand course material.

Which of the following functions is not a one-to-one correspondence? Of: R -+ R, where f(x) = 6x - 1 Of: Z - Z, where f(n) = 2n + 3 Of: R - R, where f(x) = x' - 1 Of: Z - Z, where f(n) = n - 1 A B A W N- NKX Which of the following is true about the above arrow diagram? O It properly defines a function but it is not a one-to-one function O It properly defines a function but it is not a onto O It does not define a function because z is mapped to by two elements of A O It does not define a function because B contains fewer elements than A Which of the following two pairs of sets have the same cardinality? O Rational Numbers and Irrational Numbers Real Numbers and Irrational Numbers O Integers and Irrational Numbers