The first and last terms of an A.P. are 1 and 11. If the sum of its terms is 36, then the number of terms will be

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In the given problem, we need to find the number of terms in an A.P. We are given, First term (a) = 1 Last term (an) = 11 Sum of its terms Sn = 36 Now, as we know, S_n = (n/2) ( a + l) Where, a = the first term l = the last term So, we get, 36 = (n/2)(1 + 11) 36(2) = 12n n = (36(2))/12 n = 6 Therefore, the total number of terms in the given A.P. is n = 6

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