Show that the sum of all odd integers between 1 and 1000 which are divisible by 3 is 83667.

Explanation

The odd numbers between `1 and 1000 `divisible by` 3`` are 3, 9, 15,…,999`.


Let the number of terms be ‘n’, so the `nth` term is `999`


` a = 3, d = 9-3 = 6, a_n = 999`


We know the `nth` term of an A.P is is


...