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Q3. The seventh, third and first terms of an arithmetic sequence form the first three terms of a geometric sequence. The arithmetic sequence has first term a and non-zero common difference d. (a) Show that d = (3) The seventh term of the arithmetic sequence is 3. The sum of the first n terms in the arithmetic sequence exceeds the sum of the first n terms in the geometric sequence by at least 200. (b) Find the least value of n for which this occurs. [6]