Yes, the sedative effects are additive, these two are commonly prescribed together. Do this only under medical supervision or it advised to by a doctor.
2 weeks
25 more mgs of tylenol
It can depend on the amount, and whether, or not, you legally possess them.
YES
Yes, aspirin has no known significant drug interactions with fentanyl
It is certainly possible to take a percent of a percent. For example, 10% of 250 is 25. And 10% of 25 is 2.5, and so forth.
The way to calculate this is to figure out what fraction each does in an hour (1/20 of the job, vs. 1/25 of the job). Add the fractions together to see how much they do together in an hour, then take the reciprocal to find out how many hours it takes them.
Add together 25 lots of 1.
125
Once.Because when you take away 5 from 25 it is not anymore 25 it is 20.
45-25=20 minutes
Add the numbers together and divide them by six = 181.5