A non-primitive data type is also referred to as reference type. Explain Why?

Predict the return data type of the following:

float m;
p = m/3*(Math.pow(4,3));
System.out.println(p);

Differentiate single precision and double precision data value.

Predict the return data type of the following:

int p; double q;
r = p+q;
System.out.println(r);