Question

Find the sum of the finite arithmetic series 3 + 6 + 9 + .................. + 72

Answer 1

Explanation:

3 + 6 + 9 + .................. + 72

`3 + 6 + 9 + .................. + 72 \\3 + 6 + 9 + 12 + 15 + 18 + 21 + 24 + 27 + 30 + 33 + 36 + 39 + 42 + 45 + 48 + 51 + 54 + 57 + 60 + 63 + 66 + 69 + 72 \\ 1458`

Answer 2

Hello!

3 + 6 + 9 + 12+15+18+21+24+27+30+33+36+39+42+45+48+51+54+57+60

+63+66+69+72 = 900