The power in a $\text{400 V}$ ($\text{rms}$, line-line) three-phase, three-wire $\text{RYB}$ sequence system is measured using the two wattmetters, as shown. The $\text{R}$-line current is $5\angle 60^\circ \:A$. Wattmeter $W_{1}$ in the $\text{R}$-line will read (in watt) ____________.
