Question

find the sum of all natural numbers less than 100 and divisible by 4

Answer 1

4 , 8 , 12 , 16 , 20 , ...........96
this is series in AP which first term is 4 and common difference is 4
use formula ,
Tn =a +(n-1)d
96 =4 + (n-1) 4
n=24

now,
use formula ,
Sn =n/2 {2a +(n-1) d }
=24/2 {2 x 4 +23 x 4 }= 12 x 100
=1200

Answer 2

pl mark it as brainliest