??????????
????????????
1????????????????????????????Щ???????????????????
2??????????????????10??20??30??40??50??????y???
????? ???? ???????? ?м????? ???????
10 20000
20 30000
30 50000 1??
40 80000 1??
50 100000 1??
????????????
1????????????????????????????????????????5????????????????????????????????????????á?
??????? ???? ???? ?????????
1 50000 200
2 80000 300
3 100000 500
4 200000 800
5 300000 1000 1??