[tex]\large\boxed{\begin{array}{l}\rm Um\,n\acute u mero\,\acute e\,\acute impar\,quando\,finaliza\,em\,1,3,5,7,ou\,9.\\\rm o\,n\acute umero\,que\,queremos\,obter\,tem\,a\,forma\\\rm\boxed{\rm C}\boxed{\rm D}\boxed{\rm U}\\\rm onde\,\\\rm U\longrightarrow unidade\\\rm D\longrightarrow dezena\\\rm C\longrightarrow centena.\\\rm Para\,U\,temos\,2\,possibilidades\,(1\,ou\,5).\\\rm para\,C\,temos\,5\,possibilidades\\\rm (n\tilde ao\,entra\,o\,0\,e\,nem\\\rm o\,n\acute umero\,que\,foi\,colocado\,em\,U)\end{array}}[/tex]
[tex]\large\boxed{\begin{array}{l}\rm Para\,D\,temos\,5\,possibilidades\\\rm pois\,dos\,7\,n\acute umeros\,dispon\acute iveis (0,1,2,4,5,6\,e\,8)\\\rm dois\,foram\,utilizados.\\\rm pelo\,princ\acute ipio\,fundamental\,da\,contagem\,(\bf PFC)\\\rm\underline{5}\cdot\underline{5}\cdot\underline{2}=50\,n\acute umeros.\end{array}}[/tex]
