Rachel recently joins the workforce, and her starting salary is $3,500 per month. The CPF contribution rate (both employer and employee) for her age group is 37%, and this is allocated as follows:

Ordinary account = 60% Medisave account = 22% Special account = 18%

The interest rate paid by CPF Board on members ordinary account is 2.5% per annum, compounded monthly. As Rachel intends to settle down with her fianc, she needs to set aside $25,000 in her ordinary account to buy a 4-room HDB apartment.

Using Excel =NPER function, calculate how long Rachel needs to work in order to afford the HDB apartment and examine how she can possibly accelerate this process. State the assumptions you have made.