First slide

Permutations

Question

Let A = {1, 2, 3, 4} and B = {1, 2}. Then, the number of onto functions from A to B is:

Moderate

A

8
B

14
C

12
D

None of these

Solution

Since each element of A can be associated with elements of 8 in two ways, therefore the total number of functions from A to B is 2 × 2 × 2 × 2 = 16. Out of these functions, the functions which are not onto are f (x) = 1, $\forall x \in A and f (x) = 2 \forall x \in A$ . Thus, the number of onto functions = 16 – 2 = 14.

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App