Engineering Economy 7th Edition by Leland Blank ,Anthony Tarquin

Exercise 18

The alternatives shown are to be compared on the basis of annual worth. At an interest rate of 10% per year, the values of n that you could use in the ( A/P,i,n ) factors to make a correct comparison by the annual worth method are:
a) n = 3 years for A and 3 years for B
b) n = 3 years for A and 6 years for B
c) Either
a) or b)
d) Neither
a) nor b)