to find heat, you need the following formula
heat= specific heat x mass x ΔT
specific heat (for water)= 4.184--> according to the table
mass= 100 grams
ΔT= 75 -10= 65 °C
let's plug the values.
specific heat= 4.184 x 100 x 65= 27200 joules or 27.2 Kilojoules