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Match List-I with List-II

List-IList-II
(Matrix)(Inverse of the Matrix)
(A) (174−2)\begin{pmatrix} 1 & 7 \\ 4 & -2 \end{pmatrix}(I) (2/151/10−1/151/5)\begin{pmatrix} 2/15 & 1/10 \\ -1/15 & 1/5 \end{pmatrix}
(B) (6−324)\begin{pmatrix} 6 & -3 \\ 2 & 4 \end{pmatrix}(II) (1/5−2/15−1/107/30)\begin{pmatrix} 1/5 & -2/15 \\ -1/10 & 7/30 \end{pmatrix}
(C) (52−54)\begin{pmatrix} 5 & 2 \\ -5 & 4 \end{pmatrix}(III) (1/157/302/15−1/30)\begin{pmatrix} 1/15 & 7/30 \\ 2/15 & -1/30 \end{pmatrix}
(D) (7436)\begin{pmatrix} 7 & 4 \\ 3 & 6 \end{pmatrix}(IV) (2/15−1/151/61/6)\begin{pmatrix} 2/15 & -1/15 \\ 1/6 & 1/6 \end{pmatrix}

Choose the correct answer from the options given below:

Solution

✅ Correct Option: 3

For a 2×2 matrix (abcd)\begin{pmatrix} a & b \\ c & d \end{pmatrix}, the inverse is:

A−1=1ad−bc(d−b−ca)A^{-1} = \dfrac{1}{ad - bc}\begin{pmatrix} d & -b \\ -c & a \end{pmatrix}


For Matrix (A): (174−2)\begin{pmatrix} 1 & 7 \\ 4 & -2 \end{pmatrix}

Determinant =(1)(−2)−(7)(4)=−2−28=−30= (1)(-2) - (7)(4) = -2 - 28 = -30

A−1=1−30(−2−7−41)A^{-1} = \dfrac{1}{-30}\begin{pmatrix} -2 & -7 \\ -4 & 1 \end{pmatrix}

=(2/307/304/30−1/30)= \begin{pmatrix} 2/30 & 7/30 \\ 4/30 & -1/30 \end{pmatrix}

=(1/157/302/15−1/30)= \begin{pmatrix} 1/15 & 7/30 \\ 2/15 & -1/30 \end{pmatrix}

This matches (III)


For Matrix (B): (6−324)\begin{pmatrix} 6 & -3 \\ 2 & 4 \end{pmatrix}

Determinant =(6)(4)−(−3)(2)=24+6=30= (6)(4) - (-3)(2) = 24 + 6 = 30

B−1=130(43−26)B^{-1} = \dfrac{1}{30}\begin{pmatrix} 4 & 3 \\ -2 & 6 \end{pmatrix}

=(4/303/30−2/306/30)= \begin{pmatrix} 4/30 & 3/30 \\ -2/30 & 6/30 \end{pmatrix}

=(2/151/10−1/151/5)= \begin{pmatrix} 2/15 & 1/10 \\ -1/15 & 1/5 \end{pmatrix}

This matches (I)


For Matrix (C): (52−54)\begin{pmatrix} 5 & 2 \\ -5 & 4 \end{pmatrix}

Determinant =(5)(4)−(2)(−5)=20+10=30= (5)(4) - (2)(-5) = 20 + 10 = 30

C−1=130(4−255)C^{-1} = \dfrac{1}{30}\begin{pmatrix} 4 & -2 \\ 5 & 5 \end{pmatrix}

=(4/30−2/305/305/30)= \begin{pmatrix} 4/30 & -2/30 \\ 5/30 & 5/30 \end{pmatrix}

=(2/15−1/151/61/6)= \begin{pmatrix} 2/15 & -1/15 \\ 1/6 & 1/6 \end{pmatrix}

This matches (IV)


For Matrix (D): (7436)\begin{pmatrix} 7 & 4 \\ 3 & 6 \end{pmatrix}

Determinant =(7)(6)−(4)(3)=42−12=30= (7)(6) - (4)(3) = 42 - 12 = 30

D−1=130(6−4−37)D^{-1} = \dfrac{1}{30}\begin{pmatrix} 6 & -4 \\ -3 & 7 \end{pmatrix}

=(6/30−4/30−3/307/30)= \begin{pmatrix} 6/30 & -4/30 \\ -3/30 & 7/30 \end{pmatrix}

=(1/5−2/15−1/107/30)= \begin{pmatrix} 1/5 & -2/15 \\ -1/10 & 7/30 \end{pmatrix}

This matches (II)


List-IList-II
(A)→ (III)
(B)→ (I)
(C)→ (IV)
(D)→ (II)

Therefore, the correct answer is (A)-(III), (B)-(I), (C)-(IV), (D)-(II).

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