## Answer :

'A' is the value of the account after some time.

'P' is the 'principle' ... the amount you originally put in, before any interest.

'r' is the interest rate

'n' is the number of times per year that interest is paid

't' is the number of interest payments that have happened

since you first put the money in the bank.

; where A is the value of account,P is principle , r is rate, n is frequency of interest payments per year and t is time.