Question

The value of sum $\sum _{k=1}^{\infty }(2k-1){\left(\frac{9}{11}\right)}^k$ is equal to

• A. 45
• B. 55
• C. sum of first nine natural numbers.
• D. sum of first ten natural numbers

Answer 1

Answer: (A), (C)

Correct answer is (a) 45Correct answer is (c) sum of first nine natural numbers.