In aqua-regia, a mixture of conc.HCl and conc.${\mathit{HNO}}_3$ are in the ratio of

Generally, aqua-regia is a mixture of conc. HCl and conc.${\mathit{ HNO}}_3$ in the ratio of 3:1.

This is the only solution that can dissolve gold.

As the gold bangles were dissolved in aqua-regia, their weight was reduced drastically. It also dissolves other elements like platinum.