【答案解析】税法规定的年折旧额=

=540(万元)
每年营业现金流量=税后经营净利润+折旧=500×(1-25%)+540=915(万元)
(1)NPV(4)=每年营业现金流量现值+残值现值+清理净损失减税现值-原始投资=915×(P/A,10%,4)+300×(P/F,10%,4)+540×25%×(P/F,10%,4)-3000=915×3.1699+300×0.683+135×0.683-3000=197.56(万元)
NPV(3)=每年营业现金流量现值+残值现值+清理净损失减税现值-原始投资=915×(P/A,10%,3)+300×(P/F,10%,3)+540×2×25%×(P/F,10%,3)-3000=915×2.4869+300×0.7513+540×2×0.25×0.7513-3000=-296.25(万元)
n=3+
