Please help me do discrete mathematics, by including mathematical formulas for counting techniques

37. Howmanyfunctionsaretherefromtheset {1,2,,n}, where n is a positive integer, to the set {0,1} a) that are one-to-one? b) that assign 0 to both 1 and n ? c) that assign 1 to exactly one of the positive integers less than n ? 37. Howmanyfunctionsaretherefromtheset {1,2,,n}, where n is a positive integer, to the set {0,1} a) that are one-to-one? b) that assign 0 to both 1 and n ? c) that assign 1 to exactly one of the positive integers less than n