IIMB 2001 (QA) PYQs

If $(x+y):z=\frac{11}{4},(y+z):x=26:9,$ find $(z+x):y$

There are three containers $x,y,z$. In container $x$, the ratio of milk and water is $2:1$, in container $y$ the ratio of water and milk is $2:a$. If container $x$ and $y$ are mixed in the ratio of $2:3$, to get $100$ litres of a mixture having milk and water in the ratio $3:1$. Find the value of $a.$

A and B are the two alloys of copper and brass prepared by mixing metals in the proportion of $7:2$ and $7:11$ respectively. If the two alloys are mixed in the ratio $3:2$, and melted to form a third alloy called C, then the proportion of brass and copper in C will be,