1 1

12 (Price) (Interest) (Tuition) (Fee) (Rent) (Fair)

12 (Toll) (Bribe) (Salary) (Commission) (Wage)

2

1 (1)

2

2 1 ROI

2 3

3 1

2

1 2

3 4 5

1 Cu P = 1 Rs P Cu Rs

2 I Rt P = + Cu Q I Rt Q Cu :

3 4

100105

$1.40

0.15 0.80 2.00 0.40 0.25 5.00

5

1

2

3

4 56