TITLE: What is sum of all positive odd integers less than $1000$?
QUESTION [9 upvotes]: If the sum of all positive even integers less than $1000$ is $ A $ , what is the sum of all positive odd integers less than $1000$?

REPLY [0 votes]: Consider the integers from $1$ to $10$. The even integers$\,\,(2,4,6,8)$ sum is $20$ and the odd integers $(1,3,5,7,9)$ is $25$. The difference is $5$.
For the sum of the odd integers below $1000 =10 \times 100$, we need to add $\,500=5\times 100$.
Therefore, the answer is $A+500$.
{"set_name": "stack_exchange", "score": 9, "question_id": 418682}