sauce
posted by thick .
a man deposits $8000 in his bank account.if the bank pays 8% compoud intrest per annum,what will be his total intrest after 3 years

the formula is
interest = prt 
The compound interest formula is:
A = P(1+r/n)^nt
P = principal amount (the initial amount you borrow or deposit)
r = annual rate of interest (as a decimal)
t = number of years the amount is deposited or borrowed for.
A = amount of money accumulated after n years, including interest.
n = number of times the interest is compounded per year
8000(1+.08)^1*3
Source:
depaul 
8000(1+.08)^1*3
= 8000(1.08)^3
= 10077.70 
Chopsticks is right. It is compounded annually. PRT is no compounding.