Count the number X of functions 2524227810SolutionA25242322

Count the number X of functions

:(25,24,...,22)(7,8,...,10)

Solution

A={-25,-24,-23,-22} has 4 elements

B={7,8,9,10} has 4 elements

if f is a function from A to B, then for each x in A, we need to assign an element b from B so that f(x)=b

For each x in A, we have 4 choices for f(x) ie 7,8,9 or 10

Hence, the total number of function from A->B is 4 x 4 x 4 x 4 (4 choices for each element of A)

Thus, the number of functions is 256.