1. For each of the following purchases, (a) calculate the effective interest rate of failing to take the discount, and (b) determine the date and amount paid if the discount is taken. Assume that the invoice date is March 10 and that there are 30days in a month.

(1) $500, 2/10, net 30

(2) $3,500, 4/20, net

with the formula, "Effective interest rate = discount %/(100-discount %) X 360/(FT - DP)"

what does FT and DP stand for?

and how do you know the date?