The sum of all natural numbers 'n' such that 100 < n < 200 and H.C.F. (91, n) > 1 is :

The sum of the squares of the lengths of the chords intercepted on the circle, x² + y² = 16, by the lines, x + y = n, n $$ \in $$ N, where N is the set of all natural numbers, is :

A point on the straight line, 3x + 5y = 15 which is equidistant from the coordinate axes will lie only in :

If cos($$\alpha $$ + $$\beta $$) = 3/5 ,sin ( $$\alpha $$ - $$\beta $$) = 5/13 and 0 < $$\alpha , \beta$$ < $$\pi \over 4$$, then tan(2$$\alpha $$) is equal to :