The final temperature of water is calculated using the below equation
Q= MC delta T
Q= heat energy (24500 j)
m= mass( 125 g)
c= specific heat capacity ( 4.18 j/g/c)
delta T = change in temperature ( final temperature -initial temperature)=(T-35)
final temperature is therefore=24500 j =125 g x 4.18 g/j/c x (T- 35)
24500 j=522.5 (T-35 c)
24500 j = 522.5T -18287.5
like terms together 24500 + 18287.5 =522.5 T
42787.5j =522.5 T
divide both side by 522.5 T
T=81.9 c
