Question

Find the sum of all integers between 200 and 1000 that are divisible 4

Answer 1

Answer:

Step-by-step explanation:

a=200

d=4

an=1000

an= a+(n-1) d

1000 = 200+(n-1) 4

800÷4=(n-1)

20+1 =n

n=21

Sn=n/2{2a+(n-1) d}

21/2{2.200+(21-1)4}

21/2{400+80}

21/2 *480

21*240

5040

Answer 2

hence
answer = S199 = 119400