Let A = {1, 2, 3, 4} and B = {1, 4, 9, 16}. Then the number of many-one functions f : A → B such that 1$\in$f(A) is equal to : 

Total number of functions from A to A= 4⁴ 
Number of One-one  functions from A to A= 4! 
Number of Many-one functions from A to A = 256 – 24 = 232 
Number of Many-one functions in which $1\notin \mathrm{f}\left(\mathrm{A}\right)$= 3.3.3.3 = 81 
Required number of functions =232 – 81 = 151