Answer:
14,850
Explanation:
You need the sum of
3 + 6 + 9 + 12 + ... + 294 + 297
Factor out a 3 from the sum
3 + 6 + 9 + 12 + ... + 294 + 297 = 3(1 + 2 + 3 + 4 + ... + 98 + 99)
You need to add all integers from 1 to 99 and multiply by 3.
The sum of all consecutive integers from 1 to n is:
[n(n + 1)]/2
The sum of all consecutive integers from 1 to 99 is
[99(99 + 1)]/2
The sum you need is 3 * [99(99 + 1)]/2
3 + 6 + 9 + 12 + ... + 294 + 297 =
= 3 * [99(99 + 1)]/2
= 3 * [99(100)]/2
= 3 * 9900/2
= 14,850