Question

de quantas formas 7 crianças podem formar uma roda?​

Answer 1

$\large\boxed{\begin{array}{l}\sf PC_n=(n-1)!\\\sf\\\sf PC_7=(7-1)!=6!\\\sf PC_7=6\cdot5\cdot4\cdot3\cdot2\cdot1\\\sf PC_7=720\end{array}}$