How about a 20% discount on mortgage interest?
Take an example For commercial loans, the benchmark interest rate for loans over five years is 5.94%, and the monthly interest rate is 5.94%/12=0.495%; If you enjoy a 20% discount, the interest rate is 5.94% * 0.80, and the monthly interest rate is 5.94% * 0.80/12=0.3960%. The monthly payment of 100000 10 years (120 months): [100000 * 0.396% * (1 0.396%) ^ 1