Question

A and B are two alloys of gold and copper prepared by mixing metals in the ratio 7:2 and 7:11 respectively. If equal quantities of alloys are melted to form a 3rd alloy C, the ratio of gold and copper in C will be?

Answer 1

using "isto" instead of ":"
$\frac{7}{7 + 2} + \frac{7}{7 + 11} isto \frac{2}{7 + 2} + \frac{11}{7 + 11}$
now you simplify it please :P