The ratios are not constant; therefore, the points in the table do not form a direct variation.

hmu if ur willing to do a algebra a online class i’ll pay 600 hmu on the gram profitpreme

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: