Kaplan MCQ 55 Investment appraisal

Hi John I have a problem with solution to below question: Jones Ltd plans to spend $90,000 on an item of capital equipment on 1 Jan 20x2. The expenditure is eligible for 25% tax-allowance depreciation, and Jones pays corporation tax at 30%. Tax is paid at the end of the accounting period concerned. The equipment will produce savings of $30,000 per annum for its expected useful life deemed to be receivable every 31 Dec. The equipment will be sold for $25,000 on 31 Dec 20x5. Jones has a 31 Dec year end and has a 10% post-tax cost of capital. What is the present value at 1 Jan 20x2 of the tax savings that result from the capital allowances? A) $13,170 B) $15,828 C) $16,018 D) $19,827 The way i would do it: $90,000x25%=22,500x30%=6,750 tax savings x DF10% of .909= $6,136 but there is no option to this solution I dont understand why the question asks for present value at 20x2 and the solution to this question is $15,828 where present values of tax savings from all years from 20x2 to 20x5 are added. Can you please advise? Regards Marta