GIVING EVERYTHING IF CORRECT. NO fake answers, you will be reported. And it hurts my grades so please don't.

you have to wait a while to reward brainliest if only one person answers. if 2 people answer there should be a "mark brainliest" on their question.

i cant fully remember all of the ranks, here are the ones i remember.

hand, ambitous, ace, genius.

the answer is b.

64

step-by-step explanation:

c=2πr=2·π·8≈64

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:  

is it like a multiple choice? if so then i need the multiple choice so i can get and understanding on what the answers is so that i can explain it to you