Question

find middle term of ap 6,13,20,....,216

Answer 1

An = a + (n - 1) × d
216 = 6 + (n - 1) × 7
n = 31
middle term is 16
A16 = a + (n - 1) × d
A16 = 6 + (15) × 7 = 111 ANSWER.

Answer 2

Hi,

Here is your answer,

Given data is,

a(First term) = 6 , d(common difference) = 13 - 6 = 7

Formula:- an = a + (n-1)d

 →     216 = 6 + (n - 1) × 7

 →     210 = (n-1)7

 →     n = 31

So, now the number of term is 31

Now, the middle term will be (31 + 1) ÷ 2

              = 16th term

Now, the 16th term will be T₁₆ = a + ( 16 -1 ) 7

               = 6 + ( 15 × 7)

               = 6 + (105)

                = 111

Required solution is 111.


Hope it helps you !