514. The position of an airplane that is approaching its airport is described parametrically by P = (1000, 500,900) + t[-100,_50,_90]. For what value of t is the airplane closest to the traffic control center located at (34,68,16)?

you probably already have the answer but anyways it's b. 15.0

step-by-step explanation:

the answer is b

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:  

i belive false if so your welcome if not well idk