just wondering what general area does this kind of question fall under so I can learn how to solve it.
The value of the following expression is ______
1 + 12.4D + 1.1F + 2L
You are asking how to add.
It might also be about implicit type conversion, although D isn't a literal modifier as far as I know.
If that's the case, just remember that types are always promoted to the "highest" type in any operation that takes two args of the same type.
Rough Order: double > float > int
long unsigned > long > unsigned > basic