How do I solve this?

Answer:
The heat contained is 1236 Joules
Explanation:
As we know
[tex]Q = mc\Delta[/tex]T
Where
[tex]\Delta[/tex]T is the change in temperature
m is the mass in grams
c is the specific heat of water (ice) = 2.06 joules/gram
Substituting the given values, we get -
[tex]Q = 20 * (-15+45)*2.06\\Q = 20*2.06*30\\Q = 1236[/tex]Joules