posted by RAJESH .
300 gm of water at 25°c is added to 100 gm of ice at 0°c.the temperature of the mixture is?
Since the subject is 'maths', I'm assuming the energy required for the ice-to-water conversion is not to be considered
Basically, you have to multiply the fraction of the total masses of the substance with their temperature:
Final Temp. = (300/400)*25 + (100/400)*0
= 18.75 degrees Celsius