Question

2+4+6+....+200 find n​

Answer 1

We know that form2 to 100 there are 50odd and 50 even numbers 

same with 102 to 200.

So in from 2 to 200, there are 100 even numbers.

So n=100

now we also know that the sum of even numbers starting from 2 to n terms is given by, n(n+1)

Plugging in the value of n,

We get,

100×101

10100.

Thus the sum is 10100.