An investment project costs $10,000 and has annual cash flows of $2,880 for six years. 1. What is the discounted payback period if the discount rate is zero percent?
2. What is the discounted payback period if the discount rate is 5 percent?
3. What is the discounted payback period if the discount rate is 19 percent?

1. Assuming a 0% discount rate, the cashflows will not be discounted.

Discounted Payback period will therefore be;

= 10,000/2,880

= 3.47 years

2. Assuming the discount rate was 5%, the discounted payback period is;

Trial and error;

= 2,880/1.05 + 2,880/1.05² + 2,880/1.05³

= $7,842.95

Payback will be in 4th year;

Amount left to be paid = 10,000 - 7,842.95 = $‭2,157.05‬

Cash inflow in 4th year = 2,880/1.05⁴ = $2,369.38

Discounted payback period = Year before payback + Amount left/ Amount in year of payback

= 3 + 2,157.05/2,369.38

= 3.91 years

3. Assuming 19%:

= 2,880/1.19 + 2,880/1.19² + 2,880/1.19³ + 2,880/1.19⁴ + 2,880/1.19⁵ + 2,880/1.19⁶

= $9,820.16

Project will give cash inflows for 6 years. At 6 years the investment would not have been paid off so the project will never be paid off.

are you looking for a specific answer?

answer: marginal utility of the fourth brownie is 0.

explanation: marginal utility is the addtional utility gained from the consumption of one more unit of a good. it is given by,

so, marginal utility at the 4th unit will be given by

since, the values are not given here, you can simply find marginal utility at fourth unit by subtracting total utility at 3rd unit from total utility at 4th unit.