Answer : The exit temperature of the product is, 
Explanation :
Total heat = Heat lost by liquid + Latent heat of fusion + Heat lost by frozen

where,
Q = Total heat = 6000 kJ
m = mass of product = 15 kg
= specific heat of liquid = 
= latent heat of fusion = 
= specific heat of frozen = 
= initial temperature of liquid = 
= final temperature of liquid = 
= initial temperature of frozen = ?
= final temperature of frozen = 
Now put all the given value in the above expression, we get:
![6000kJ=[15kg\times 4kJ/kg^oC\times (10-2)^oC]+[15kg\times 275kJ/kg]+[15kg\times 2.5kJ/kg^oC\times (2-T_3)^oC]](https://tex.z-dn.net/?f=6000kJ%3D%5B15kg%5Ctimes%204kJ%2Fkg%5EoC%5Ctimes%20%2810-2%29%5EoC%5D%2B%5B15kg%5Ctimes%20275kJ%2Fkg%5D%2B%5B15kg%5Ctimes%202.5kJ%2Fkg%5EoC%5Ctimes%20%282-T_3%29%5EoC%5D)

Thus, the exit temperature of the product is, 