JEE Main 2021 Chemistry question

When 400 mL of 0.2M solution is mixed with 600 mL of 0.1 M NaOH solution, the increase in temperature of the final solution isK. (Round off to the nearest integer). [Use : (aq) + OH(aq): = –57.1 kJ Specific heat of = 4.18 J density of = 1.0 g Assume no change in volume of solution on mixing.]