The number of onto functions from the set \(\{1, 2, 3, 4\}\) to the set \(\{a, b\}\) is
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 14
Each of the 4 elements can be sent to a or to b, so the total number of functions is
\(2^4 = 16\)
A function is onto when both a and b are images. Only two of the 16 functions miss an element:
all four elements sent to a
all four elements sent to b
So the number of onto functions is
\(16 - 2 = 14\)