You are taking a math test and get 32 problems right and 13 problems wrong what percent of the test did you get right

The total number of problems is 45.

The fraction of correct answers is 32/45 = 0.7111...

in percent that is about 71.1%

a is the correct

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: