Multiple choice

The sum of the first n terms of a series is 31, and the sum of the first n – 1 terms of the series is 20. What is the value of nth term in the series?

  1. 9

  2. 11

  3. 20

  4. 31

  5. 51
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The nth term of a series is the difference between the sum of the first n terms and the sum of the first n-1 terms. nth term = S_n - S_{n-1} = 31 - 20 = 11.

AI explanation

The value of the nth term is the difference between the sum of the first n terms and the sum of the first n - 1 terms. Therefore, the nth term is 31 - 20 = 11.

Keep practicing — related questions