We have the next information
100 mg of menthol
every minute the amount of menthol in your body is cut in half
we have the next variables
x= minutes
y= amount of menthol in mg remaining in your body
so the equation that can we model is
![y=100(0.5)^x](https://img.qammunity.org/2023/formulas/mathematics/college/9x5j6waszi21uzmsi0ipdz0qqc8lq7p4i5.png)
then we have that It is safe to take a new cough drop after the level of menthol in your body is less than 5 mg
y= 5mg
![5=100(0.5)^x](https://img.qammunity.org/2023/formulas/mathematics/college/9d5uleexh22w74ynfha3prkaqpdyxk3387.png)
in order to know the time we need to solve the equation above
![\begin{gathered} (0.5)^x=(5)/(100) \\ (0.5)^x=0.05 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/e5p6kkclplkk7poqwndx2892ow713bz2tm.png)
then we isolate the x
![x=4.32](https://img.qammunity.org/2023/formulas/mathematics/college/xa02mg7qfef03dzh8qoo8xo5ghalp5lcbx.png)
after 5 minutes you can take another cough drop