If A = {a, b, c} and B = {−2, −1, 0, 1, 2}, write the total number of one-one functions from A to B.
Question:
If A = {a, b, c} and B = {−2, −1, 0, 1, 2}, write the total number of one-one functions from A to B.
Solution:
Let $f: A \rightarrow B$ be a one-one function.
Then, $f(a)$ can take 5 values, $f(b)$ can take 4 values and $f(c)$ can take 3 values.
Then, the number of one-one functions = 5