Find the sum of all even numbers from 1 to 350.

The even natural number between 1 to 350 is
2,4, 6, …….348
Where first term a = 2
Second term t₁ = 4
Third term t₂ = 6
Thus, common difference d = t₂ – t₁ = 6 – 4 = 2
t_n = 348 (As we have to find the sum of even numbers between 1 and 350 therefore excluding 350)
Now, by using n^th term of an A.P. formula t_n = a + (n – 1) d
where n = number of terms
a = first term
d = common difference
t_n = n^th terms
we can find value of “n” by substituting all the value in formula we get,
⇒ 348 = 2 + (n – 1) × 2
⇒ 348 – 2 = 2(n – 1)
⇒ 346 = 2(n – 1)