Multiple choice

Calculate the sum of the following arithmetic series: $1 + 5 + 9 + 13 + 17 + ...... to\ 30 $ terms.

  1. $1500$
  2. $1700$
  3. $1550$
  4. $1770$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This is an arithmetic progression with a=1, d=4, and n=30. The sum formula is S = (n/2) * (2a + (n-1)d). S = (30/2) * (2*1 + 29*4) = 15 * (2 + 116) = 15 * 118 = 1770.

AI explanation

Using the sum formula for an arithmetic series, Sn = n/2 * (2a + (n-1)d). Here, the first term a is 1, the common difference d is 4 (5 - 1), and the number of terms n is 30. Substituting these values gives S30 = 30/2 * (2*1 + (30-1)*4) = 15 * (2 + 116) = 15 * 118 = 1770.

Keep practicing — related questions