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 .
Answer
392
Solution
Exactly one of 1, ,98 goes to 1: 98 C1=98 ways; the other 97 go to 0 (1 way).
99 and 100 are free: 2 2=4 ways
98 4=392
Answer: 392