Question

find the middle term of AP 6 13 20 ​

Answer 1

Correct questions

=> Find the Middle term of AP 6 , 13 , 20 , ........... , 216

Solution:-

Given:-

=> First term ( a ) = 6

=> Common difference ( d ) = 13 - 6 = 7

=> Tₙ = 216

Formula

=> Tₙ = a + ( n - 1 )d

We get

=> 216 = 6 + ( n - 1 ) × 7

=> 216 = 6 + 7n - 7

=> 216 = 7n - 1

=> 217 = 7n

=> n = 31

Now we have to find middle term

=> We know that when n is odd we can write as ( n + 1 )/2

=> middle term =( 31 + 1) /2

=> Middle term = 32 /2

=> Middle term is 16