Explanation:
When ice tends to absorb heat energy then it will change into liquid state. Now, change in the temperature of cold water
=
Change in the temperature of original water in the container 
Latent heat of melting of ice L = 80 cal/g
Specific heat of water C = 1 cal/g C
Heat absorbed by ice to melt = mass(
) x latent heat(L)
Heat absorbed by water = mass(
) x specific heat(C) x change in temperature (dT')
= 0.050 kg = 50 g and
= 0.50 kg = 500 g
Now, heat lost by water is as follows.
heat lost by hot water( at
) = heat absorbed by the ice + heat absorbed by cold water
So, we will cancel out 50 from each term given above. Hence,
= 720

Thus, we can conclude that final temperature of the water is
.