18-The profitability index (PI) rule can be best stated as:

Select one:

a. An investment is acceptable if its PI is less than one.

b. An investment is acceptable if its PI is less than its payback.

c. An investment is acceptable if its PI is greater than one.

d. An investment is acceptable if its PI is less than the net present value (NPV).

e. An investment is acceptable if its PI is greater than the internal rate of return (IRR).

19-Which one of the following would have the greatest present value, assuming a positive discount rate?

Select one:

a. $1,000 today plus $400 a month for six months.

b. $1,000 today plus $200 a month for a year.

c. $1,000 today plus $100 a month for 2 years.

d. $2,200 today plus $200 a month for six months.

e. $2,200 today plus $100 a month for a year.

20-You collect model cars. One particular model increases in value at a rate of 5% per year. Today, the model is worth $29.50. How much additional money can you make if you wait ten years to sell the model rather than selling it five years from now?

Select one:

a. $10.40

b. $11.24

c. $11.03

d. $10.86

e. $9.98

-Just the correct answers (Letters), without any explanation at all, please!

- Just answer please if you are 100% sure about the answers; many thanks!