Let S be the set of all triangles in the xy-plane, each having one vertex at the origin and the other two vertices lie on coordinate axes with integral coordinates. If each triangle in S has area 50 sq. units, then the number of elements in the set S is :

The area of the region

A = {(x, y) : 0 $$ \le $$ y $$ \le $$x |x| + 1  and  $$-$$1 $$ \le $$ x $$ \le $$1} in sq. units, is :

If the system of linear equations
x $$-$$ 4y + 7z = g
       3y $$-$$ 5z = h
$$-$$2x + 5y $$-$$ 9z = k
is consistent, then :

Let z₀ be a root of the quadratic equation, x² + x + 1 = 0, If z = 3 + 6iz$$_0^{81}$$ $$-$$ 3iz$$_0^{93}$$, then arg z is equal to :