this is the answer. this should help
Answer : The substances half life in days is, 5.6 days.
Step-by-step explanation :
Half life : It is defined as the amount of time taken by a radioactive material to decay to half of its original value.
All radioactive decays follow first order kinetics.
The relation between the half-life and rate constant is:

where,
k = rate constant = 0.1235 per days
= half-life
Now put all the given values in the above formula, we get:


Thus, the substances half life in days is, 5.6 days.
One way to solve it is writing two equations based on the info so
y = 5x + 10 for members
y = 6x for nonmembers
(the + 10 isn't included in the second equation because nonmembers won't pay a membership fee)
and to find their intersection point (where the values will be the same), you just set them equal to each other:
5x + 10 = 6x
subtract 5x
x = 10 classes
Answer:
It's C
Step-by-step explanation:
I just took the test