Question

The sum of all the natural number from 200 to 600​

Answer 1

800*401/2=160400

is the answee

Answer 2

Solution:

Natural numbers from 200 to

600 are

200,201,202, .....,600 are in A.P

first term (a) = 200

common difference (d) = a2-a1

= 201-200 = 1

number of terms from x=200,to

y = 600 is y-x+1 = 600-200+1

= 401

n = 401

Sum of n terms (Sn)

= (n/2)[first term+last term ]

= (401/2) [ 200+600]

= (401/2)×800

= 401 × 400

= 160400

Therefore ,

Required sum = 160400