Groups and FieldsChallengeA Gallery of Groups ShareA Gallery of Groups · Challenge problemHow many upper-triangular matrices (ab0d)\begin{pmatrix}a&b\\0&d\end{pmatrix}(a0bd) lie in GL(2,Z5)GL(2,\mathbb Z_5)GL(2,Z5)?Check Show answer Walk through it step by step Practice more like this Review this concept