Question

Find the sum of integers from 11to1000 which are divisible by 3​

Answer 1

Answer:

Integer that are divisible by 3from 11to 1000 are

12,15,18.............................999

Now, Sum =12+15+18....................+999

=3(4+5+6...............+333)

We know that, sum of first n integers n(n+1)/2

It can also be written as

S=3[(1+2+3+4+5+6............+333) -(1+2+3)]

=3[{333(334)}-(6)]

=3*[55605]

=166815

This is your answer.

Plzz mark as brainlist.