Question

Find the sum of all natural numbers between 250 and 1000 which are exactly divisible by 3

Answer 1

is it right I am not sure

Answer 2

In a.p. first no: 252 , d=3 ,. an = 999 hence, now , an = a+(n-1) × d, 999= 252+(n-1) × 3. 999-252=(n-1)× 3. 747÷3=n-1. 249 = n-1. 249+1 =n. 250 =n now, sn= n÷2(a+an). sn = 250÷2(252+999). sn= 125(1251). sn =48785