???????????????н???????? ????????????20?40?????????????

????С???????????o?????20???40??????????????????????ο???￡?????????????????20???40??????????????а?????

(???????????е???????)

????20?????1000(10*10*10)??????????

????? 2?????1???????90(10*9)???????9/100??

????? 3???????10???????1/100??

????? 3???????900???????1/10??

?????40?????343(7*7*7)??????????

????? 2?????1???????42(7*6)???????6/49??

????? 3???????7???????1/49??

????? 3???????294???????1/7??

????????

???9/100*550+1/100*5000+1/10*150=49.5+50+15=114.5

????6/49*550+1/49*5000+1/7*150≈67.3+112+21.4≈201

(“/”????????“*”????)

???2?????1????????550????;

3????????5000????;

3????????150???顣

?????40??ο????????20???

?20:114.5*2=229

?40: 201

?????￡??20???40???????

??????￡?

?????????????????*????????*??????+...

???????????1???????????“*1”??

???????????

????????????????

????????????????????

???????????????????????

????????????????????

??????°???????????????潲??

???????R????????????

?????????????40407??????????http://audiogearreviews.com/hjdz/