Question

Find the number of all onto functions from the set A to itself when A contains 10 elements.​

Answer 1

ANSWER

Taking set {1,2,3}

Since f is onto,all elements of{1,2,3} have unique pre-image.

Total no. of one-one function=3×2×1=6

eg:-Since f is onto,all elements of {1,2,3} have unique pre-image.

total no. of onto functions=n×n−1×n−2×2×1=n!

solution