Let S = {1, 2, 3, … , 100}. The number of non-empty subsets A of S such that the product of elements in A is even is :

In a class of 140 students numbered 1 to 140, all even numbered students opted Mathematics course, those whose number is divisible by 3 opted Physics course and those whose number is divisible by 5 opted Chemistry course. Then the number of students who did not opt for any of the three courses is

Let N denote the set of all natural numbers. Define two binary relations on N as _R = {(x, y) $$ \in $$ N $$ \times $$ N : 2x + y = 10} and R₂ = {(x, y) $$ \in $$ N $$ \times $$ N : x + 2y = 10}. Then :

Two sets A and B are as under :

A = {($$a$$, b) $$ \in $$ R $$ \times $$ R : |$$a$$ - 5| < 1 and |b - 5| < 1};

B = {($$a$$, b) $$ \in $$ R $$ \times $$ R : 4($$a$$ - 6)² + 9(b - 5)² $$ \le $$ 36 };

Then