How create the following function in matlab

1)Existing matrix in matlab, Input:

A =

   1     2     3     4     5     6     7     8    9

2) Generate random integer between 10 to 20

3)Replace 3 events within matrix A

4) Output:

B=

     1     2    11     4    17     6     7    15     9

Output has 3 elements replaced in the range of 10 to 20.