Answer 1

The size of the space alloted when object is created, equals to the total size on data members. Since member functions pool shared among multiple objects of the same class, it size is not taken into account.

example
class demo {
int x; // 4 bytes
int y; // 4 bytes
float z; // 4 bytes
...
};

Data size = 4 + 4 + 4 = 12 bytes