Question

A goldsmith mixes 10oz of a 30% gold alloy with 20oz of a 15% gold alloy. What is the percent concentration of the resulting alloy?

Answer 1

10 oz of a 30 % gold alloy

20 oz of a 15 % gold alloy

`\begin{gathered} 10.30\text{ \% + 20.15 \% = 30. x} \\ (30)/(100)*10+(15)/(100)*20=30x \end{gathered}`
`\begin{gathered} 0.3(10)+0.15(20)=30x \\ 3+3=30x \\ 6=30x \\ x=(6)/(30) \\ x=0.2 \end{gathered}`

0.2 to percentage

= 0.2 x 100 = 20 %

Hence the percent concentration = 20 %

Therefore the percent concentration of the resulting alloy = 20%