A.75°C
Let the change in temp of cold water be  x degrees,
while that of  hot water be 100 - x degrees.
Heat exchange =  mcΔt
Ice
Δt = x
m = 0.50 kg
c = 4.18 kJ/kg*°C
Hot water
Δt = 100 - x
m = 1.5 kg
c = 4.18
But;
Heat lost = heat gained
0.50 * c * x = 1.5 * c * (100 - x) Â Â Â Â Â
0.50 *x = 1.5*(100 - x) Â Â Â Â Â Â Â Â Â Â Â Â Â
0.5x = 150 - 1.5x                 Â
0.5x + 1.5x = 150 - 1.5x + 1.5x      Â
2x = 150 Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â
x = 75° C
Hence; the equilbrium temperature will be 75° C