I need help with these simple interest questions.

Determine the amount of interest on a 90-day note for $437.00 with interest at 6.19% per annum. Ignore any grace period. The amount of interest is $ (Round the final answer to the nearest cent as needed. Round all intermediate values to six decimal places as needed.)Find the present value, on the date indicated, of the following promissory note. Ignore any grace period. A non-interest-bearing note for $600.00 issued August 20, 2010, for 153 days if money is worth 7.9%, on October 30, 2010. The value on October 30, 2010 is $ -| (Round the final answer to the nearest cent as needed. Round all intermediate values to six decimal places as needed.)The maturity value of a seven-month promissory note issued July 31, 2017, is $3275. What is the present value of the note of the date of issue if interest is 7.75%? Ignore any grace period. The present value is $]. (Round to the nearest cent as needed.)