1. Daniel rolls a 6-sided number cube 36 times. How many times should he expect to roll a 4? A 9

B 4

C 6

D 10​

something over 10 so ? /10

step-by-step explanation:

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: