If the p^{th} term of an AP is q and the q^{th} term is p. P.T its n^{th} term is (p+q-n).
Ans: APQ
a_{p} = q
a_{q} = p
a_{n} = ?
a + (p-1) d = q
a + (q-1) d = p
d[p - q] = q - p Sub d = -1 to get ⇒ = -1 ⇒ a = q + p -1 a_{n} = a + (n - 1)d
= a + (n - 1)d
= (q + p - 1) + (n - 1) - 1 an = (q + p - n)