Can someone help me with this Exponential Growth and Decay word problem? I have been able to get the rest of them done but this one stumps me...

option A is the correct answer.

Step-by-step explanation:

Looking at the table, the amount of medicine in her system is decreasing constantly with time. This constant amount by which this amount of medicine is decreasing is the decay constant.

Decay constant = 350/400 = 306.25/ 350 = 0.875

Let y represent the amount of medicine in her system after t hours.

Let a represent the initial amount of medicine in her system.

Let b represent the decay constant.

Let t represent the number of hours. Therefore, the function representing the exponential decay would be

y = 400b^t

When she wakes up at 7.00 am, the time from 5.00 pm would be 14 hours. Therefore

y = 400 × 0.875^14

y = 61.7 mg