Question

amount after 5 years if $800 is invested at 3%

Answer 1

to find the simple interest,
\[SI=\frac{ P \times R \times T }{ 100 }\]
SI=Simple Interest
P=Principal ($800)
R=Rate (3)
T=Time (5)

Answer 2

after you have found the simple interest, add it to the principal (original amount paid to the bank) to find the total money you would have at the end of 5 years..