Question

8) If a, b, care in A.P., then a+b, c+a and a+b are in
a) A.P b) G.P
c) H.P d) None

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Answer 1

I think this answer will be helpful for you

When a,b,c are in A.P.,

First term is t1=a

Second term t2=a+d=b

third term is t3=a+2d=c

Now a+c=a+(a+2d)=2a+2d=2(a+d)=2b

⇒a+c=2b