text: how much is 18.25 million dollars worth in a bank that pays 5% interest be worth if it's  year 1848 to now this is the amount that usa paid mexico for the land at the time in order to be fair and give this back how much would they owe us . i believe the equation for solving this is: s=p(1+i)^n  where s is the amount after n periods, p is the initial principal and i is the interest rate.  therefore s=18,250,000(1+.05)^(158) assuming annual compounding.   the answer is (drum-roll) $40,660,440,000.