How can i write a story problem that involves adding fractions with unlike denominators include the solution

An example will be: Sarah bought 1 pie for her birthday party. She cut it up into 12 slices. During the party she eats 2 of the pie and her Friend Carly eats 1 of the pie. How much pie
                                         12                                                          6
is left? The answer will be 4 = 1  of the cake is left.
                                          12   3                                                                                   
                                           

The internet will you