Question

Q17 ?What is the answer

Answer 1

Answer:

given ap = a1,a2,a3 ...

        a4/a7  = 2/3

we can say that  a4 = a+3d ;  a7=a+6d

                 (a+3d)/(a+6d) = 2/3  

                         3(a+3d)   = 2(a+6d)     [ cross multiplying]

                          3a+9d    = 2a+12d

                            3a -2a  = 12d-9d

                                  a   = 3d -----------------------(1)

we need to find a6/a8

               (a+5d) / (a+7d)

subtituting the value of a from equation (1)

            = (3d+5d) / 3d+7d)

                  =  8d/10d

                   = 8/10

                 =4/5

hence a4/a7 = 4/5