Answer: (a) 6%
(b) 10.61%
(c) Yes
Step-by-step explanation:
a) After tax cost of debt = Yield (1- tax) 
 = 8 ( 1 - 0.25) 
 = 8 × 0.75
 = 6%
b) 



 = 0.1061 or 10.61%
Note: Cost of preferred stock is not tax deductible 
 c),Yes the treasurer is correct ,The cost of debt is 5% less than cost of preferred stock [10.61 - 6 = 4.61%]