Simple Interest

Because simple interest is used on short$-$term notes, the time period is often given in days rather than months or years. We convert this to years by dividing by $360,$ assuming a $360$ day year called a banker's year.

Question $1$

$50pts$

Use a banker's year described above to answer this question.

To complete the sale of a house, the you accept a $310-$day note for $$9,000$ at $8\%$ simple interest. $($Both interest and principal are repaid at the end of the $310$ days.$)$ Wishing to use the money sooner for the purchase of another house, the you sell the note to a third party for $$9,180$ after $30$ days. What annual simple interest rate will the third party receive for the investment? Express your answer as a percentage.

$\%.$ Round to the nearest thousandths of a percent $(3$ decimal places$).$

Question $2$

$50pts$

Use a banker's year described above to answer this question.

T$-$bills $($Treasury bills$)$ are one of the instruments the U$.$S$.$ Treasury Department uses to finance public debt. If you buy a $280-$day T$-$bill with a maturity value of $$18,750$ for $$18,456\mathrm{.}93,$ what annual simple interest rate will you earn? Express your answer as a percentage.

$\%.$ Round to the nearest thousandths of a percent $(3$ decimal places$).$