Question

6. Which term of the A.P 3.8.13.18......... is 78?​

Answer 1

Hope it helps you plz mark as brilliant answer

Answer 2

Answer:  n = 16

Step-by-step explanation:     here we have , a = 3 , d = a2 - a1 = 8 - 3 = 5

we should take 78 as nth term

and

as we know that ,

                          nth term of an a.p. = a + (n - 1)d

by substituting values we get , 78 = 3 + (n - 1 )5

                                                   78 - 3 = 5n - 5

                                                   75 + 5 = 5n

                                                   80/5 = n

                                                    n = 80/ 5

                                                    n = 16 which is the required answer