Quick refresher on arithmetic and geometric progressions – straightforward, and lists just the formulae. Not a whole lot.
These are useful only tangentially in finance, yet it would be useful to remember the formulae for arithmetic and geometric progressions in case there is an question on the exam.
Arithmetic progression
If a be the first term of an arithmetic progression (AP), n the number of terms, and d the common difference, then:
Sum to n terms of an AP = 
Geometric progression
The sum to n terms of a GP where r is the common difference is:
if r is less than 1, and
if r is greater than 1.