The rule of the fixed annual interest is

A is the new amount
P is the initial amount
r is the rate in decimal
t is the time in years
Since the initial amount is $248,000, then
P = 248000
Since the annual rate is 3.8%, then
r = 3.8/100 = 0.038
Since the time is 30 years, then
t = 30
Substitute them in the rule above to find the new amount

The new amount is $759,228.12
To find the total interest subtract P from A

The total interest Divya pays is $511,228.12 to the nearest cent