Question

Find the sum of all numbers between 5 and 250 which are exactly divisible by 4

Answer 1

use (2n+1)


I am not an expert but try

Answer 2

Answer:

S61=7808

Explanation:

a1=8

an=248

n=61

substitute by (n/2)(a1+an)

(61/2)(8+248)

S61=7808