Question

The A.P of 5 have 55 terms find the mean of the sequence​

Answer 1

Step-by-step explanation:

Answer

Let the terms in the arithmetic progression be a,a+d,a+2d,a+3d and a+4d .

Given the sum of these terms

=5a+10d=55

Hence a+2d=11

So T3=11 also given t4=5+t1+t2

Hence a+3d=5+a+a+d

So 2d=5+a

Adding a on both sides we get

a+2d=5+2a

But a+2d=t3=11

Hence 11=5+2a

So a=3

Also 2d=5+a hence d=4

Hence the series will be

3,7,11,15,19