Purple Turtle Group buys on terms of 1.5/10, net 60 from its chief supplier.
If Purple Turtle receives an invoice for $1,889.99, what would be the true price of this invoice?

a) $1,954.72 b) $1,861.64 c) $2,327.05 d) $1,303.15

The nominal annual cost of the trade credit extended by the supplier is:

a) 13.10% b) 13.76% c) 11.10% d) 11.54%

The effective annual rate of interest on trade credit is .
Suppose Purple Turtle does not take advantage of the discount and then chooses to pay its supplier late, so that on average, Purple Turtle will pay its supplier on the 65th day after the sale.
As a result, Purple Turtle can decrease its nominal cost of trade credit by % by paying late.