Since people can have both Aadhar card and voter id. In such case also, y are eligible to apply for Ration card so phrase used is inclusive or.

?Two and two makes four? and ?Elephant is heavier than ant? are true so y are statements. ?A prime number is always odd? is false as prime number may be even so it is a statement. ?Sum of and b is 5? is not a statement as it can be true or false based on values of a and b taken.

?0 is a positive or negative number? is formed by connecting given statements using or.

Negation of all angles is ?not all angles?. So, negation of given statement is ?There is at least one angle different in equilateral triangle?, ?It is false that all angles are equal in equilateral triangle?, ?It is not case that all angles are equal in equilateral triangle?. But ?All angles are unequal in equilateral triangle? cannot be negation of given statement as this does not include isosceles triangles.

If p n q means q is necessary condition for p or p => q. It is not same as p is necessary condition for q.

If p n q statement will be true if-
If p is true n q must be true and if q is true n p must be true.

If p n q means p is sufficient condition for q or p=>q. It is not same as q is sufficient condition for p.

We know, any integer cannot be positive as well as negative simultaneously so ?or? is exclusive. Hence it is false.

The compound statement with ?And? can be true if all its component statements are true. If this condition is not satisfied, compound statement cannot be true.
1 is neir less than 2 nor less than 3 so it is false. 43 is prime number as well as odd so it is true.
0 is neir positive number nor negative number. 16 is not divisible by 3 so it is false.

If we write ?q if and only if p? n it means q <=> p i.e. p=> q and q=> p.
And if we write ?p if and only if q? n it means p <=> q i.e. q=> p and p=> q.
So, both are exactly same.