When the superintendent received the letter of complaint from the banker’s wife, he … and laughed unpleasantly tore it up sent it back

(Bn) геометрическая прогрессия             Bn(в квадрате)=Bn-1 * Bn+1 (свойство г.п)

B2=2                                                       B3( в квадрате)=6 * 2/3

B4=2/3                                                    B3(в квадрате)=4

q-?                                                          B3=2

B1-?                                                        q=Bn+1/Bn

                                                              q=B3/B2

                                                               q= 2/6

                                                              q=1/3

                                                               B2=B1*q

                                                               B1=B2/q

                                                               B1=6/ 1/3= 6*3=18