I have 6 terms in order a, b, c, d, e, f. What is/are the middle term/s?
c,d
Consider the term c. There are 2 terms before it-a, b. There are 3 terms after it-d, e and f. Consider term d. There are 2 terms after it, and 3 terms before it.
Hence we see that there are 2 terms before c and 2 terms after d. c and d are adjacent terms. Hence c and d both are the median terms.