I think it would be 64/100 because 64 percent is most likely out of 100 percent
Answer:
Option A. 10 years
Step-by-step explanation:
we know that
Half-life 
is the amount of time required for a quantity to fall to half its value as measured at the beginning of the time period.
In this problem of a radioactive isotope is 10 years, which means that after 10 years half of the sample would have decayed and half would be left as it is.
After 10 years ( first half life) 5/2 = 2.5 g decays and 2.5 g remains left
Answer: 50 minutes
Change 1 hour 45 minutes into minutes by adding 60 to 45.
60 + 45 = 105
Shes watched 55 minutes so we subtract that from 100 to get our answer
105 - 55 = 50
