In a geometric series the second term is 3, the fifth term is 81.

Question

Find the third term?

Answer 1

Let the second term in the geometric series be a2 = 3

Let the fifth term in the geometric series be a5 = 81

In a geometric series the nth term

 Given that        and    

                                                    

                                                                              

                                                              

                                                                

                                                                

  Therefore

  Therefore the third term

                                             

Therefore the third term