Question

Find the first and last term of an AP whose middle term is 8

Answer 1

There is only one middle term. Therefore, total no of terms is odd.

Now,
a(n+1/2)= a + (n+1/2 - 1) d
  8         = a + (n-1/2)d
   16        = 2a + (n-1)d       [Taking 2 as the LCM]
    16       = a + an.
Sum of first and last term is 16.
Therefore,
 a = 16- an
an= 16-a

Hope it helped!
NISHTHA.