答:年折旧额=24000/5=4800元利润=48000-38000-4800=5200元投资利润率=利润/投资总额*100%=5200/2400*100%=21.67%
答:年折旧额=24000/5=4800元利润=48000-38000-4800=5200元投资利润率=年平均利润/平均投资总额=5200/12000*100%=43.33%