At the moment a certain medicine. Is injected, it's concentration in the blood stream is 120 mg/L. From that moment forward, the medicine concentration drop by 30% each hour. Write a function that gives the medicines concentration in milligrams Per liter, C (t), t hours after the medicine was injected

C (t) = 120 (0.7) ^t

Step-by-step explanation:

From that moment forward, the medicine concentration drop by 30% each hour. It means that the rate at which the medicine concentration is dropping is exponential. We would apply the formula for exponential decay which is expressed as

A = P (1 - r) ^t

Where

P represents the initial concentration.

A represents the final concentration after t hours.

t represents the number of hours.

r represents the rate

From the information given

P = 120 mg/L

r = 30% = 30/100 = 0.3

The expression becomes

C (t) = 120 (1 - 0.3) ^t

C (t) = 120 (0.7) ^t