Let the cold water go up x degrees.
Let the hot water go down 100 - x degrees.
The formula for heat exchange is m*c*delta t
Givens
Ice
deltat = x
m = 0.50 kg
c = 4.18
Hot water
deltat = 100 - x
m = 1.5 kg
c = 4.18
Formula
The heat up = heat down
0.50 * c * x = 1.5 * c * (100 - x) Â Â Â Â Â Â Divide both sides by c
Solution
0.50 *x = 1.5*(100 - x) Â Â Â Â Â Â Â Â Â Â Â Â Â Remove the brackets.
0.5x = 150 - 1.5x                  Add 1.5x to both sides.
0.5x + 1.5x = 150 - 1.5x + 1.5x       Combine like terms 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 Divide by 2
x = 75
Answer
A