The number of onto function from the set 1,2,3,4,5,6,7,8,9,10,11 to the set 1,2,3,4,5,6,7,8,9,10 is

Question

The number of onto function from the set 1,2,3,4,5,6,7,8,9,10,11 to the set 1,2,3,4,5,6,7,8,9,10 is (A) 5 × 11 ! (B) 10 ! (C) (11 !/2) (D) 10 × 11 !

Tardigrade Admin · Accepted Answer

11 C 2 × 10 C 1 × 9 !=(11 !/2) × 10=5 × 11 !

Q. The number of onto function from the set ${1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11}$ to the set ${1, 2, 3, 4, 5, 6, 7, 8, 9, 10}$ is