UCB Accounting Corporate Finance Monthly Mortgage Payment Questions

I’m working on a accounting exercise and need the explanation and answer to help me learn.

Question 1: Calculation Monthly Mortgage Payment: 

Information : You find a house $500,000 and put down 20% downpayment with 5.5% and 20-year loan payment period. 

Question 2: Calculation 28/36 Rule

28 Rule: 

[1] P&I – that is your monthly mortgage payment from question 1
    Tax Escrow – $1,000
    Insurance Escrow $ 100
   Total                                

[2] Gross Income : 85,000 / 12 month

[3] Total monthly mortgage payment / monthly gross income 

36 Rule: 

[A] Long Term debt Payment 

Car loan payment     $450
Credit card payment $600
Personal Loan Pyt     $300
Total                                    

[B] Total monthly mortgage payment + Total L/T debt Payment

[C] Total overall payment / Monthly Gross Income