100 points! Please help me understand how to do this :)

Determine the amount of heat needed to raise the temperature of 20.0 g of ice at 0 degrees Celsius to water at 80 degrees Celsius.

Find the amount of heat lost by 85 g of water at 95 degrees Celsius to ice at -35 degrees Celsius.

How much heat is needed to raise the temperature of 50.0 g of ice at -10 degrees Celsius to form steam at 120 degrees Celsius?