Forces and equilibrium — practice question

The diagram depicts three particles $A$, $B$ and $C$ suspended in equilibrium, with each one attached to the end of a string. The other ends of the three strings are fastened together at the point $X$. The strings supporting $A$ and $C$ pass over smooth fixed horizontal pegs $P_1$ and $P_2$ respectively. The weights of $A$, $B$ and $C$ are $5.5\,\text{N}$, $7.3\,\text{N}$ and $W\,\text{N}$ respectively, and the angle $P_1XP_2$ is a right angle.