Question

Let A ≡ {1, 2, 3, 4}, B = {a, b, c}, then the number of function from A→ B, which are not onto is

(A)  81

(B)  24

(C)  8

(D)  45

Answer 1

Correct option   (D) 45

Explanation :

The number of onto function from A → B is the coefficient of

The total number of functions is 81. Hence, the required number of functions is 

81 − 36 = 45