Question

Let E = {1, 2, 3, 4} and F = {1, 2}, Then, the number of onto functions from E to F is 

(a) 14 

(b) 16 

(c) 12 

(d) 8

Answer 1

The correct option(a) 14

Explanation:

The number of onto functions from 

E = {7, 2, 3, 4} to F = {1, 2} 

= Total number of functions which map d to F - number of functions for which map  

f(x) = 1 and f(x) = 2 for all x ∈ E 

= 2⁴ - 2 = 14