The number of one-one functions from set {a, b, c} to itself are:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 6
In a one-one function different elements have different images, so each image used once cannot be used again:
\(f(a): 3 \text{ choices}\)
\(f(b): 2 \text{ choices}\)
\(f(c): 1 \text{ choice}\)
\(\text{Number of one-one functions} = 3\times 2\times 1 = 3! = 6\)
NCERT (2026-27 edition):
Relations and Functions
