Final answer:
After 3 hours, 92.12 milligrams of caffeine will remain in the body from an initial amount of 150 milligrams, considering a 15% hourly decrease in caffeine level.
Step-by-step explanation:
To calculate the amount of caffeine remaining in your body after 3 hours, when the starting amount is 150 milligrams and it decreases by 15% each hour, you can use the formula for exponential decay:

Where:
- C(t) is the amount of caffeine remaining after t hours
- C0 is the initial amount of caffeine
- r is the rate of decrease (15% or 0.15)
- t is the time in hours
Plugging in the values, we get:


C(3) = 150 × 0.614125
C(3) = 92.119 (rounded to hundredths place)
Therefore, 92.12 milligrams of caffeine will remain in the body after 3 hours.