List-I (Compound) | List-II (Uses) |
---|---|
(A) Iodoform | (I) Fire extinguisher |
(B) Carbon tetrachloride | (II) Insecticide |
(C) CFC | (III) Antiseptic |
(D) DDT | (IV) Refrigerants |
Iodoform $\rightarrow$ Antiseptic
CCl$_4$ $\rightarrow$ Fire extinguisher
CFC $\rightarrow$ Refrigerants
DDT $\rightarrow$ Insecticide
Thus, the correct match is:
\[\boxed{\text{A-III, B-I, C-IV, D-II}}\]
Let \( S = \left\{ m \in \mathbb{Z} : A^m + A^m = 3I - A^{-6} \right\} \), where
\[ A = \begin{bmatrix} 2 & -1 \\ 1 & 0 \end{bmatrix} \]Then \( n(S) \) is equal to ______.