Question

If the am between pth and qth terms of an ap be equal and to the am between rth and sth terms of the ap then show that p+q=r+s

Answer 1

I think I'm right!!!

Answer 2

Answer:

pth,qth and rth term are q,p,p+q−r respectively.

ap=a+(p−1)d=q

=a+pd−d=q

aq=a+(q−1)d=p

=a+qd−d=p

Now for getting common difference we should minus 2nd term from first term that means pth term minus qth term. which is

aq−ap ⇒ d = 1

But in my book it is given

ap−aq

after solving

⇒ d=1