Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Determinants

Question:

The value of the determinant $\begin{vmatrix}10! &11! &12!\\11! &12! &13!\\12! &13! &14!\end{vmatrix}$, is

Options:

2 (10!11!)

2 (10!13!)

2 (10!11!12!)

2 (11!12!13!)

Correct Answer:

2 (10!11!12!)

Explanation:

We have,

$\begin{vmatrix}10! &11! &12!\\11! &12! &13!\\12! &13! &14!\end{vmatrix}$

$=10!×11!×12!\begin{vmatrix}1 &11 &132\\1 &12 &156\\1 &13 &182\end{vmatrix}$

$=10!×11!×12!\begin{vmatrix}1 &11 &132\\0 &1 &24\\0 &1 &26\end{vmatrix}$  [Applying $R_2 → R_2-R_1, R_3→R_3-R_2$

$=2(10!×11!×12!)$