Answer
$r=3.73$
Work Step by Step
From tables A-4 to A-6:
Inlet 1 ($P_1=1\ MPa, T_1=50°C$): $h_1=209.34\ kJ/kg$
Inlet 2 ($P_2=1\ MPa, T_1=200°C$): $h_2=2828.3\ kJ/kg$
Outlet ($P_3=1\ MPa$, sat. liquid): $h_3=762.51\ kJ/kg$
From the energy balance:
$\dot{m}_1h_1+\dot{m}_2h_2=(\dot{m}_1+\dot{m}_2)h_3$
With $r=\dot{m}_1/\dot{m}_2$
$rh_1+h_2=(r+1)h_3$
$r =\frac{h_2-h_3}{h_3-h_1}$
Hence $r=3.73$