Given angle 1 and angle 2 are suplements angles and angle 4 are suplemntsand angle 1 = angle 4 prove angle 2 = angle 3

answer: both chords and diameters have two endpoints on a circle. diameters must intersect the center of a circle.

the answer is 1030 it's very simple math.

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: