NO.PZ2016012102000133
问题如下：
Ted Ltd. recently purchased a manufactoring machine for $60,000, which is expected to generate annual cash inflow of $25,000 for six years. The firm will depreciate the machine over six years for accounting purpose. However, the tax authority estimates the machine's useful life of 5 years. Assume tax rate is 40%, and the machines has no salvage value. What is the income tax expense of Ted Ltd. in year 6 if straight-line method is used?
选项：
A. $10,000.
B. $5,200.
C. $6,000.
解释：
C is correct.
考点: 递延所得税的计算
解析：题目问第六年的income tax expense，也就是financial accounting的所得税费用。
Income tax expense = Current tax expense + ΔDTL - ΔDTA
Current tax expense =Taxable income×Current tax rate
accounting base 和tax base 的数字指的是depreciable asset扣掉累积折旧的账面价值。第五年年末的时候，accounting base 账面价值还剩10000，tax base 账面已经是零，所以DTL算出来是4000，第六年年末的的时候accounting base和tax base都是零了，所以第六年就没有DTL了，也就是之前累积的DTL第六年实际上已经回转了。
前期税务局算的折旧费用多，公司交的税少，第六年的时候，税务局算的报表已经没有折旧费用了，所以算的应税所得就高了，公司应该交的税就高了，相当于是前期少交的税这一年要补交上了。所以第六年没有新增的DTL，反而是把以前攒下的DTL回转了，相当于△DTL就等于-4000，所以income tax expense是10,000-4,000=6000
第六年的current tax expense=25000×40%=10000
第六年的Income tax expense=10000+(-4000)=6000
公式我能理解，但是具体是怎么算出来48000 以及递减的这个，请教老师
