arithmetic progression - The sum of an arithmetic series is \sum_{r = 1}^{n} (80 - 3r)

Krishna (last edited 5 years ago) (Expert, Educator @Qalaxia)

Step 1: To find the 1st term, plug in n = 1. in the sequence and simplify

[NOTE: Knowing that, n represents the position of a term in the sequence. So change the n values.]

Step 2: To find the 2nd term, plug in n = 2. In the sequence and simplify

Step 3: Take the various n values and substitute in the sequence, till you get the required sequence.

Step 4: Calculate the common difference

[FORMULA: If Arithmetic Progression is a, a + d, a + 2d, a + 3d .........,

Then Common difference = Succeeding(a+2d) ± Preceding(a+d) term = d]