A person takes 200 milligrams of an antibiotic. Each hour, the remaining dosage in the person's blood stream decreases by 1/3.
Demitri and Kendal are trying to figure out how many milligrams are left in the person's bloodstream after 5 hours.
Demitri says that approximately 0.82 milligrams of the medication remains, because 200(1/3)^5 ≈0.82.
Kendal says that this can't be correct.
Who is correct and why? Select all correct answers
A) Demitri is correct. The equation 200(13)5≈0.82. is correct.
B) Demitri is correct. One-third of 200 is about 66.67. One-third of 66.67 is about 22.22. Do this a 3rd time and you get about 7.4. A 4th time gives you about 2.47. And a 5th time gives you about 0.82.
C) Kendal is correct. The fraction 13 is the rate of decay, not the growth factor.
D) Kendal is correct. If 200 decreases by 13, you get approx. 133.33. Do that again and you get about 88.89. Do that a 3rd time, you get about 59.29. A fourth time gives you about 39.51. And a 5th time gives you about 26.34.
I agree with Kendall because I when you decrease a number you are supposed to make it into a percentage, and then take away "1" which is what I did, and her answer ended up being correct. But I am not entirely sure it is.
1 answer
and, you are correct.