If A={1,2,3,4} and B={5,7,9}, then the number of onto function from A to B is
A
36
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
B
45
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
81
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
64
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution
The correct option is A36 If the set A has n elements and set B has r elements, then the number of onto function from set A to set B is equivalent to distributing n distinct objects into r distinct boxes such that each box gets at least one object.
Total number of onto functions =rn−rC1(r−1)n+rC2(r−2)n−......