Took a $500,000 mortgage to purchase a main home with a fair market value of $800,000. 
February 2022: Took out a home equity loan of $25,000 to put on the main home. Both loans are secured. 
What percentage of the interest paid on the loans is deductible on the tax return? 
a) 0% 
b) 50% 
c) 75% 
d) 100%