Question

C. 11260
D. 12260
1. The sum of two numbers is 300 and their difference is 150. Find the numbers​

Answer 1

Step-by-step explanation:

We know that sum of first n natural numbers is (n*(n+1))/2.

First we can perform Sum of first 300 natural numbers is (300*301)/2=45150.

Then we can perform sum of first 149 natural numbers is (149*150)/2=11175.

Now if you subtract sum of first 149 natural numbers from sum of first 300 natural numbers then we will get sum of natural numbers from 150 to 300, i.e 45150–11175=33975.

Or you can directly use formulas, those are n/2(a+l) or n/2(2a+(n+1)d), but above one is some different way to think.