Let us consider three alloys of which the first alloy contains zinc, tin, and copper in the ratio 2:3:4; the second alloy contains zinc, tin, and copper in the ratio 3:4:5 and, the third alloy contains zinc, tin, and copper in the ratio 4:5:6

1. When the three alloys are melted together in the ratio p:q:r, the ratio of zinc, tin, and copper in the resulting alloy is also p:q:r. Determine the ratio p:q:r
2. What is the ratio p:q:r, if keeping all the other conditions unaltered, the ratio of zinc, tin, and copper in the resulting alloy is r:q:p?

Note: Assume that each of p, q, and r is a positive integer with gcd(p,q,r)=1