Question

German silver is a mixture of copper, nickel and zinc. $\frac{3}{4}$ of the total mass is copper and $\frac{3}{8}$ of the remainder is nickel. What mass of German silver will contain $8\frac{1}{2}$ kg of zinc?

• A. $45\frac{2}{5}$kg
• B. $50\frac{1}{5}$kg
• C. $68$ kg
• D. $54\frac{2}{5}$kg

Answer 1

The correct option is D $54\frac{2}{5}$kg

Let us assume total mass of German silver is $x$

Given that,

$\frac{3}{4}$ of mass is copper

$\Rightarrow$ Remaining mass is $\frac{1}{4}x$

Also, $\frac{3}{8}$ of this remaining mass is nickel, i.e. $\frac{5}{8}$ of $\frac{1}{4}x$ is Zinc.

$\therefore$ Zinc $=\frac{5}{32}x=\frac{17}{2}$kg

Mass of German Silver $=\frac{272}{5}=54\frac{2}{5}$kg