The half-life of iodine-131 is 8.0 days.
A sample of iodine-131 prepared for thyroid radiotherapy has an initial activity of 3.20 MBq3.20\text{ MBq}3.20 MBq at 12:00 on 3rd November.
Estimate the activity of this sample at 12:00 on 27th November of the same year.