What's the minimum degree by which an octagon can rotate to map onto itself

the answer is d. (1.2, -4.7) on edgn

hope this !

ending amount = beginning amount / (2^n)

where "n" = number of half-lives (or elapsed time / half-life)

ending amount = 50 mg / (2 ^10 / 5.3)

ending amount = 50 mg / (2 ^ 1.8867924528)

ending amount = 50 m / 3.6981210597

ending amount = 13.5203794557 mg

or about 13.5 mg remain

source:  

-1/4 > -1 2/3. -1/4 is greater than -1 2/3 because it is closer to 0 on the number line.