a$.)$ Compute for Payback Period:

b$.)$ Compute for the Discounted Payback Period:

Year $1-5000$

Year $2-3000$

Year $3-4000$

Year $4-0$

Year $5-5000$

Year $6-3000$

Year $7-2000$

Year $8-1000$

Year $9-0$

Year $10-1000$

Required rate of Return $-10\%$

Initial Investment $-15,000$