Question

find the sum of all numbers between 100 and 200 which are not divisibleby 5 answer

Answer 1

ans = sum of all between the 100 and 200 minus sum of nos divisible by 5
ans =
$\frac{99}{2} (101 + 199) - \frac{19}{2} (105 + 195)$
=14850-2850
=12,000