I had a very huge excel assignment to do, and finished it all except for this small part of it, so I wish someone could help me with it:

A bank makes an announcement for an HP Compaq notebook with the following offer:
Repayment in 36 monthly installments of USD 57
or Repayment in 24 monthly installments of USD 82.
What is Cash Value of this Notebook? (PV)

I even sent an email to my instructor asking him for a small hint and he replied: You should use one PMT function to solve the other (like in school , use X to find Y) and then u should use the " what if utilities".

so what needs to be solved here is the present value and the annual rate..

Anyone has any idea what are the formulas i should write in?

Thank you in advance