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SubjectsMathematics
अनुक्रम का nवाँ पद
In this Class 9 Mathematics topic from Sequences and Progressions, students learn how to find the nth term of a sequence by connecting a term’s position with its value. The topic focuses especially on arithmetic progressions, where each term changes by a constant common difference, using the formula aₙ = a + (n − 1)d. Students practise identifying patterns, finding missing or distant terms, checking whether a number belongs to a sequence, and applying the method to clear numerical and real-life problems.
Correct answer: C. \(81\left(\frac{1}{3}\right)^{n-1}\)
Explanation: Each term is multiplied by \(\frac{1}{3}\), so \(a_n=81\left(\frac{1}{3}\right)^{n-1}\). Keep the first term fixed and use exponent (n-1).
