Question

ACCORDING TO NATIONAL DEBT CLOCK IN 2012 THE UNITED STATES NATIONAL DEBT WAS $15.2 TRILLION. ASSUME THIS NUMBER IS YOUR BASE AMOUNT AND IS STAYING FIXED AS YOU SOLVE
A)if the population of the US at the time was 312 million, what was your share of the national debt?
B) Asuuming an interest rate of 5% how fast was the debt increasing per year in 2012 due to interest?
C) Assuming a 366-day year (2012 is a leap year), how fast was the debt increasing per minute in 2012 due to interest?
D)Assume you finish college in 201. How much interest would accure from 2012 to 2018 if no payments were made?

Answer 1

Base amount = National debt of USA in 2012 = $ 15.2 trillion

It is not clear for B, C, D if the amounts are national or your share of debt. So I find both. You take what ever is needed.

A) Population = 312 million. = number of people in the USA in 2012
   Your share of the debt is National Debt divided by the size of population
     your share = $ 15.2 trillion / 312 million
                     = $ 15.2 * million * million / 312 * million
                     = $ 15.2 * 1,000,000 / 312
                     = $ 48,717.95  after rounding to 2nd decimal

B) Increase in debt = interest on the debt = debt * r /100, where r = interest rate
                     = $ 15.2 trillion * 5 /100 = $ (15.2 * 1000 billion) * 5/100
    increase in national debt  = $ 760 billion per year

   Increase in your share of debt = $48,717 * 5/100 = $ 2,435.85 per annum

C) 2012 is a leap year. so 366 days instead of 365.
           Interest per year = $760 billion = $ 760,000 million
           Number of minutes in 2012 = 366 * 24 * 60 = 527040 minutes

       Increase in debt per minute = $ 760, 000 million / 527040 minutes
                                                 = $ 1.44201578 million per minute
                                                 = $ 1,442,015.78 per minute

      Increase in your share of debt per minute = $ 2,435.85 / 527040 minutes
                                                 = $ 0.004621 per minute

D)
      Interest accrued from 2012 to 2018: it becomes compound interest for
      6 years compounded annually.
        
     Total accrued debt amount in 2018 = $ 15.2 (1+5/100)⁶ trillion
                 = $ 15.2 * 1.05⁶ trillion = $ 20.34 trillion

     Interest accrued in 2018 = 
              = total debt in 2018 - debt in 2012 = $ 20.34 trillion - $ 15.2 trillion
              = $ 5.14 trillion