Usually interest rates refer to an annual rate and 5% of $50,000 is
0.05 $50,000 = $2,500
There are 365 days in a year so 40 days is ^{40}/_{365} of a year. Hence the interest on $50,000 at an annual rate of 5% for 40 days is
$2,500 ^{40}/_{365} = $273.97
Penny
