Year 12s: what will be the first way you research your future options? >>

Is the solution bank wrong?

In the second line, all the numbers in the first bracket should not be a multiple of 3, but there's a 99? The second bracket represents all the multiples of 3 under 100.

Forgot to add the original question

Spoiler

(edited 7 years ago)

Reply 1

Denisi007

Original post by ColossalAtom

In the second line, all the numbers in the first bracket should not be a multiple of 3, but there's a 99? The second bracket represents all the multiples of 3 under 100.

Well what's it is doing is summing the whole series between 1 and 99 then subtracting all the multiples of 3 so you are left WITHOUT the multiples of 3 as the question asks :smile:

Reply 2

ColossalAtom

Original post by Denisi007

Well what's it is doing is summing the whole series between 1 and 99 then subtracting all the multiples of 3 so you are left WITHOUT the multiples of 3 as the question asks :smile:

Thanks, I was wondering why the 99 was in the non-multiple 3 bracket. But then I saw that 3 as well...