Answer
2 or greater: $\frac{5}{6}$
4 or less: $\frac{4}{6}$, or $\frac{2}{3}$
9 years: $\frac{2}{6}$, or $\frac{1}{3}$
Work Step by Step
There are 6 bills total.
5 out of the 6 have a lifespan of 2 years or greater (5, 10, 20, 50, and 100). This is represented by the fraction $\frac{5}{6}$.
4 of the 6 have a lifespan of 4 years or less (1, 5, 10, and 20). This is represented by the fraction $\frac{4}{6}$, which can be simplified to $\frac{2}{3}$.
2 of the 6 have a lifespan of 9 years (50 and 100). This is represented by the fraction $\frac{2}{6}$, which simplifies to $\frac{1}{3}$.