$($please solve step by step$)$

A system is composed of a turbine and an adiabatic heat exchanger $($fluids are not mixing to each other$)$ as shown in the figure below. The working fluid of the system is water, the process is steadystate and all the necessary information is provided in the figure.

i$.$ Calculate the mass flowrate, $m_1^{}=m_2^{}=m_3^{}$ in $k\frac{g}{s}$

ii$.$ Calculate the entropy generation in the heat exchanger

iii. Calculate the turbine inlet temperature

iv$.$ Calculate the isentropic turbine efficiency