➷ Calculate the number of hours:
24 x 3 = 72
72/13 = 5.5....
This is 5 whole half lives
You have to half the value 5 times
149/2 = 74.5
74.5/2 = 37.25
37.25/2 = 18.625
18.625/2 = 9.3125
9.3125/2 = 4.65625
The closest value is B. 3.21 so that should be the answer
➶ Hope This Helps You!
➶ Good Luck (:
➶ Have A Great Day ^-^
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