1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
coin_cost = 0.0 bill_cost = 0.0 i = 0.02 year = 0 while year < 90: bill_cost += 0.027*1e9 year += 4.5 bill_cost*=(1+i)**4.5 year = 0 while year < 90: coin_cost += 0.15*1e9 year += 30 coin_cost*=(1+i)**30 print bill_cost-coin_cost
1
-89885158.5712