Q7 of 110 Page 65

If a1, a2 , a3,...are in A.P. such that , then the 13th term of the A.P. is

Given

Let common ratio be d


a4 = a1 + 3d


a7 = a1 + 6d



2a1 + 6d = 3a1 + 18d


a1 + 12d = 0


Which corresponds to the 13th term (a1 + (13-1)d) = 0


Therefore, the correct option is B.

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