Functions Ques 4
- Let $E=\{1,2,3,4\}$ and $F=\{1,2\}$. Then, the number of onto functions from $E$ to $F$ is
(2001, 1M)
(a) $14$
(b) $16$
(c) $12$
(d) $8$
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Answer:
Correct Answer: 4.(a)
Solution: (a) The number of onto functions from
$E=\{1,2,3,4\}$ to $F=\{1,2\}$
$=$ Total number of functions which map $E$ to $F$ - Number of functions for which map $f(x)=1$ and
$f(x)=2$ for all $x \in E=2^4-2=14$