Question

find the number of integers between 32 and 395 that are divisible by 6

find their sum

Answer 1

least number between the given range =36; to find the maximum no. divide 395 by 6 ;we get remainder to be 5 ;Therefore 395-5 will purely divided by 6 and also be the maximum no. in the given range
Also total nos.:390=36+(n-1)6
calculate for n ; then apply
36+42+......+390=n/2(36+390) & get the result

Answer 2

so if i apply that to this question
find the number of negative integer greater than -500 that are divisible by 33 and find the sum

i got n=15
sum=-3960