Let us first write down the weight of the three individual people mentioned in the question. this will help in solving the problem.
Weight of Hannah = 7.5
Weight of Wilson = 11.6
Weight of Dillon = 28.9
Now
Combined weight of Hannah and Dillon = 7.5 + 28.9
= 36.4
Now
Difference between the combined weight of
Hannah and Dillon and the individual weight of Wilson = 36.4 - 11.6
= 24.8
So the difference between the combined weight of Hannah and Dillon with the individual weight of Wilson is 24.8