Resposta :
12 + x = total de alunos
meninos/meninas = 2/3
12 * 2/3 => 24/3 => 8
12 + 8 = 20 alunos o total.;)
meninos/meninas = 2/3
12 * 2/3 => 24/3 => 8
12 + 8 = 20 alunos o total.;)