Given the equation:

You know that the radioactive substance has this half-life (in years)

And:

Therefore, you can rewrite the equation in this form in order to find "k":

Solve for "k":
Answer:
the answer might be -23 I think but I would I advise to wait until another person answer this question
Answer:
350.5
Step-by-step explanation:
Answer:
0.468 or 65/139, 46.8%
Step-by-step explanation:
P(green) = 45 / 139
P(yellow) = 20 / 139
Add them together for either one:
65 / 139 = 0.468 = 46.8%
Answer:
9.0625%
Step-by-step explanation:
It increased from 320 to 349
This is a percent INCREASE.
320 is the "old" value and 349 is the "new" value.
We find percent increase by the formula:

Where old is 320 and new is 349. Lets substitute and find the increase (percentage):

The percentage increase is 9.0625%