Question

tell me answer fast ......✨✨give me method of solving

Answer 1

First,
What do you mean by onto function?
Answer is onto function means a function in which co-domain = range.

Now let's find total number of functions from A to B.
Total number of functions = 2^(Number of elements in A)

Total number of functions = 2^4 = 16

But we have to subtract that functions which are not onto functions.

a function in which all elements of A points to element {1} of B will be not a onto function from A to B,

and other function in which all elements of A points to element {2} of B will be not a onto function from A to B.

Total number of onto functions from A to B
= Total number of functions from A to B - Function which are not onto functions from A to B

= 16 - 2

= 14

"Thanks"