For what value of $$\mathrm{a}$$ and $$\mathrm{b}$$ the intercepts cut off on the co-ordinate axes by the line $$a x-b y+8=0$$ are equal in length but opposite in signs to those cut off by the line $$2 x-3 y+6=0$$ on the axes
$$ \text { If A }(\operatorname{adj} A)=5 I \text {, where I is the identity matrix of order } 3 \text {, then }|\operatorname{adj} A|= $$
A student has 3 library cards and 8 books of his interest in the library. Out of these 8 books he does not want to borrow Chemistry part 2 unless he can borrow Chemistry part 1 also. In how many ways can he choose the three books to be borrowed?
The dimensions of the largest rectangle of side $$x$$ and $$y$$ that can be inscribed in the right angled triangle of sides $$\mathrm{a}$$ and $$\mathrm{b}$$ is