please quickly answer

A mixed preheater containing 10 cubic meters of solution at 25 degrees Celsius is heated by a heater with a coil. Saturated steam at 130 degrees Celsius is used in the heat exchanger (take it as fluid temperature). The heat transfer coefficient of the heat exchanger is hOAO=UA=150 kcal/min degrees Celsius. The molar temperature of the solution can be taken as C=1kcal/kg degrees Celsius and its density as 800kg/ cubic meter. Heating should be stopped when the solution temperature reaches 70 degrees Celsius. It will be assumed that there is no heat leakage from the mixing tank to the environment and Tm=T will be taken a) After how many minutes does the steam inlet have to be closed? b) What will be the temperature of the solution in the tank after 15 minutes