A firm with a 12.5 percent cost of capital is considering a project for this years capital budget. The projects expected after-tax cash flows are as follows:

Year:	0	1	2	3	4
Cash flow:	-$15,000	$6,300	$7,100	$6,600	$5,400

Calculate the projects discounted payback period.

Selected Answer:	a. 2.18 years
Answers:	a. 2.18 years
	b. 2.00 years
	c. 3.00 years
	d. 2.50 years
	e. 2.82 years

please show formula used to solve?