Question

The generalised form of 199 is:​

Answer 1

Generalised for 199 = (2*100) - 1

Answer 2

Step-by-step explanation:

By numbers, I've assuming you're referring to natural numbers.

This is an arithmetic progression, with a common difference d=1 . The first term a=1 and the last term an=199 .

an=a+(n−1)d=n

⇒n=199

Therefore, there are 199 terms. Now,

S=n2⋅(a+an)=12⋅199⋅200=100⋅199=19900 .