I can't help notice the upper-right-corner picture of "no calculators allowed".
the rate for the prior 50 years has been that,
1950 1/3 of americans were blue-eyed.
2000 1/6 of americans were blue-eyed
so in 50 years, it went from 1/3 to 1/6, well, low and behold, 1/6 is half of 1/3
[tex] \bf \cfrac{\quad \frac{1}{3}\quad }{2}\implies \cfrac{\quad \frac{1}{3}\quad }{\frac{2}{1}}\implies \cfrac{1}{3}\cdot \cfrac{1}{2}\implies \cfrac{1}{6} [/tex]
so, in 2050, namely in 50 years from 2000, we can expect that it'll drop to another half then,
[tex] \bf \cfrac{\quad \frac{1}{6}\quad }{2}\implies \cfrac{\quad \frac{1}{6}\quad }{\frac{2}{1}}\implies \cfrac{1}{6}\cdot \cfrac{1}{2}\implies \cfrac{1}{12} [/tex]
