Răspuns:
m,impur=127g
m,impuritate ?
m,impuritate-=m,Ag impur-m,Ag pur
p=m,purx100/m,impur---> m,pur= 127x85/100g=107,95g
m,impuritate= 127-107,95=>19,05g
m,Au pur= 492,5x80/100g=394g
m,impuritate= 492,5-394=>98,5g
m,impuritate, total= 19,05+98,5=>117,55g
Explicație: