UPSEE Solved Model Paper 7

Given:
A = {1, 2, 3} and B = (a, b, c}
We have to find the maximum number of mappings f and g, where f is a function from A to B
and g is an one-one function from A to B
Now,
A = {1,2, 3} ⇒ n(A) = m = 3
B = {a, b, c) ⇒ n(B) = n = 3
Since number of f mappings from A to B is
= n(B)n(A) = nm = 33 = 27
and number of one-one functions g from A to B is
= n(n - 1) ... [n - (m - 1)]
= 3 . 2 . 1 = 6
Hence, option 'C' is correct