Set this up as
10 = 40 (1/2)t/28
and solve for t in years.
10/40 = (1/2)t/28
log(0.25) = (t/28) log(0.5)
t = 28 log(0.25) / log(0.5) years = 56 years
Test the answer:
56 years = 2(28 years) = 2 half-lives, so the remaining amount should be 1/2 of 1/2 of the initial amount, i.e. 1/4 of the initial amount, and 10 mg = 1/4 of 40 mg.
Precious gems would be my best guess, it's the only natural rescource that's only in one area. Sooo.... Precious gems i guess
When the value of a country’s currency falls, the currency is depreciating, so one unit of that currency can buy fewer units of other currency.
A depreciation of a country's currency makes its export goods cheaper for foreigners and domestic residents find that foreign imports are more expensive.
Because many American Conservatives believe that NAFTA has leeched our labour force and fed "American Jobs" to the Mexican economy. Many NAFTA skeptics cite the loss of U.S. manufacturing jobs as a reason to criticize NAFTA and to be wary of future trade deals. According to the CFR, the U.S. auto sector lost roughly 350,000 jobs between 1994 and 2016. Many of those jobs were taken up by workers in Mexico, where the auto sector added over 400,000 jobs in the same period.
Besides that (the main and largest reason), the only other reasons are that NAFTA hurt the economic prospects of Mexican small farmers and small business owners, and that NAFTA suppressed wages for non-college-educated workers in the U.S.
