标题: 请教一道数学题，求各位NN们帮忙~ [打印本页] 作者: freddxy 时间: 2013-1-30 17:13 标题: 请教一道数学题，求各位NN们帮忙~ At a certain supplier, a machine of type A costs $20,000 and a machine of type B costs $50,000.Each machine can be purchased by making a 20 percent down payment and repaying the remainder of the cost and the finance charges over a period of time.If the finance charges are equal to 40 percent of the remainder of the cost, how much less would 2 machines of type A cost than 1 machine of type B under this arrangement?
【思路】Machine A: 40000 down payment:8000 remainder: 40000-8000=32000 finance charge: 12800 total:40000（疑惑：这里应该是40000*0.8啊）+12800=52800 Machine B: 50000 down payment:10000 remainder:50000-10000=40000 finance charge: 16000 total: 50000（这里也有问题）+16000=66000 difference between two arrangement:66000-52800=
我觉得不对啊~ 条件1：Each machine can be purchased by making a 20 percent down payment and repaying the remainder of the cost and the finance charges over a period of time. 条件2：If the finance charges are equal to 40 percent of the remainder of the cost 那么总的花费应该是根据条件一repaying the remainder of the cost + the finance charges over a period of time 而finance charges是根据条件二 即总的花费=0.8*原价+0.8*原价*0.4 所以这样算来应该选B。求牛人帮忙！谢谢！可能我的逻辑不对。