Question

find the sum of 2+5+8+...upto31 term

Answer 1

Answer:

1457.

Step-by-step explanation:

$a = 2 \\ \\ d = 3 \\ \\ a31 = 2 + (30) \times 3 \\ = 2 + 90 \\ = 92 \\ \\ s31 = \frac{31}{2} (2 + 92) \\ \\ = \frac{31}{2} (94) \\ \\ = 31 \times 47 \\ \\ = 1457.$