Question

A tumor is injected with 2 grams of Iodine-125, which has a decay rate of 2% per day.
Write an exponential model representing the amount of Iodine-125 remaining in the
tumor after t days. Then use the formula to find the amount of Iodine-125 that would
remain in the tumor after 10 days.
Someone please help

Answer 1

Exponential decay formula is:

Total = start value x(1- rate) ^ time

Using the values given you get:

Total = 2(1-0.02)^t

Simplified :

Total = 2(0.98)^t

Now replace t with 10 and solve for total:

Total = 2(0.98)^10

Total = 1.634 grams left after 10 days. Round answer as needed.