`m_{ZnS} = 5.80\% = 4 (tấn)`

Ta có:

`ZnS -> Zn`

`97(g) -> 65(g)`

`4(tấn)-> a(tấn)`

`=> a = (4.65)/(97) = (260)/(97) (tấn)`

`=> m_{Zn} = (260)/(97) . 90\% = (234)/(97) (tấn)`

`6m = 600cm`

`40mm = 4cm`

`80mm = 8cm`

`20 mu m = 0,002 cm`

`V_{ống} = 600.4.8 = 19200 (cm^3)`

Khi tráng kẽm lên

`V_{ống} = 600. (4 + 0,002.2).(8 + 0,002.2) = 19228,8096(cm^3)`

`=> V_{Zn (tráng)} = 19228,8096-19200 = 28,8096(cm^3)`

`=> m_{Zn(tráng)} = 28,8096.7,14 =205,7(g)`

`=> x = ( (234)/(97) .10^6)/(205,7) = 11728` (ống)