September 2021 Question 9

Hi, I am looking at this question and there appears to be quite a useful formula that the variance of the accumulated amount is
[1+2j+j^2+s^2]^n -(1+j)^2n. I havent seen this in the course notes and was wondering if this is ok for me to assume is true going forwards?

I have see a couple of these types of questions and have the 2023 version of the revision notes and can find them all in booklet 2, but there isnt much about this in the latest course notes - are the types of questions in booklet 2 still examinable? thank you

 

Thank you John - thats really helpful