Answer
Yes, there is an inverse. $\triangle = 5000$
Work Step by Step
Let's perform row operations to get an easier matrix. $$ 3 \begin{vmatrix} 10 & 0 & 20/3 \\ 0 & -10 & -20 \\ 40 & 0 & 10 \\ \end{vmatrix}$$
We then subtract 4 times row 1 from row 3 to get...
$$ 3 \begin{vmatrix} 10 & 0 & 20/3 \\ 0 & -10 & -20 \\ 0 & 0 & -50/3 \\ \end{vmatrix}$$ The determinant of a triangular matrix is the product of the diagonals, $10*-10*-50/3*3 = 5000$
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