#### (i) If a_{n} = 3 – 4n, show that a_{1}, a_{2}, a_{3}, … form an A.P. Also find S_{20}.

(ii) Find the common difference of an A.P. whose first term is 5 and the sum of the first four terms is half the sum of the next four terms.

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#### The sum of first n terms of an A.P. whose first term is 8 and the common difference is 20 equal to the sum of first 2n terms of another A.P. whose first term is -30 and the common difference is 8. Find n.

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