Q.

Number of functions f:{1,2,...,100}{0,1}, that assign 1 to exactly one of the positive integers less than or equal to 98, is equal to __________.          [2025]


Ans.

(392)

Given : f:{1,2,...,100}{0,1}

Number of ways to connect {1, 2, ..., 98} to 1 = 98

Number 99 can connect either 0 or 1  2 ways

Similarly, 100 can connect either 0 or 1  2 ways

   Total number of functions for the given condition that assign 1 to exactly one of positive integers  98 is given by 98×2×2 = 392.