<p>the sum of the first n positive odd integers is equal to n^2. what is the sum of odd integers between 100 and 300 ?
ans : 20000</p>
<p>There are 150 odd positive integers less than 300, so 1+3+…+299 = 150^2 = 22500.</p>
<p>Also, there are 50 odd positive integers less than 100, so 1+3+…+99 = 50^2 = 2500</p>
<p>Subtracting the two above equations, we have 101+103+…+299 = 20000.</p>
<p>thnks a lot :)</p>