H $=$ $$300,000$

LTV $=80$

Term $=30$ years

R $=6\%$

Expected period of ownership: $6$ years

Broker$$s commission at sale $=$ $$21,493$Appraisal fees spent over the holding period $=$ $$1,000$

Cosmetic repairs for sale $=$ $$3,600$Maintenance costs $($total for $6$ years of stay$)=$ $$20,000$

Property tax $=$ $$21,387$

Property insurance $($total for $6$ years$)=$ $$4,700$Savings on tax deduction $=$ $$5,988$RMB$72=$ $$219,355$

PMTs $=$ $$103,602$

Int $=$ $$82,957$

PrRed $=$ $$20,645$

How did they calculate the Interest of $82,957$ and PrRed of $$20,645.$ What are the steps to get those numbers?