You deposit 800 dollars into your savings account how much simple interest will 800 dollars earn in 6 months at 7.25%

First, converting R percent to r a decimal
r = R/100 = 7.25%/100 = 0.0725 per year,
putting time into years for simplicity,
6 months ÷ 12 months/year = 0.5 years,
then, solving our equation

A = 800(1 + (0.0725 × 0.5)) = 829 
A = $ 829.00

The total amount accrued, principal plus interest,
from simple interest on a principal of $ 800.00
at a rate of 7.25% per year
for 0.5 years (6 months) is $ 829.00.