Answer:
a) The after-tax cost if she pays the bill in December is $21,700
b) The after-tax cost if she pays the bill in January is $19,306.80
Step-by-step explanation:
a) If she pays the $31,000 bill in December
Present value tax savings = amount × marginal tax rate
= $31,000 × 30%
= $9,300
After-tax cost = Pre-tax cost - present value tax
= $31,000 - $9,300
= $ 21,700
b) If she pays the $31,000 bill in January
Present value tax savings = amount × marginal tax rate
= $31,000 × 40%
= $12,400
Calculation of discount factor = Present value =
=
= 0.943
Present value tax savings = amount × discount factor
= $ 12,400 × 0.943
= $11,693.20
After-tax cost = Pre-tax cost - present value tax
= $31,000 - $11,693.20
= $ 19,306.80