Problem:
Compute the rank of
$\left(
\begin{array}{cccc}
 1 & 9 & 5 & 5 \\
 6 & -8 & 2 & 1 \\
 2 & 2 & 1 & -7 \\
\end{array}
\right)$.
Answer:
$3$
{'source': 'AMPS', 'file': 'amps/mathematica/linear_algebra/rank_and_nullity/20161.txt'}