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What is the value of n if the middle term (x + 2y)^2n + 1 is the 19^th term?(a) 33(b) 34(c) 35(d) 38I got this question in class test.I want to ask this question from Binomial Theorem topic in chapter Binomial Theorem of Mathematics – Class 11

Answer» RIGHT answer is (c) 35

The EXPLANATION is: Clearly (2n + 1) is an odd NUMBER. Therefore this is a case of BINOMIAL with an odd power.

For a binomial expansion with odd power, there are two middle terms.

Case 1: \(\frac{n+1}{2}\) = 19

Therefore n = 37

Case 2: \(\frac{n+3}{2}\) = 19

Therefore n = 35


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