Answer to Question #63529 in Atomic and Nuclear Physics for rose

Question

calculate the half lives of the following samples.
1. A sample of iodine-123 whose activity falls from 1000 Bq to 250 Bq in 14.4 hours.
2.A sample of technetium -99m whose activity falls from 200 Bq to 25 Bq in 18 hours.
3. A sample of strontium-90 whose activity falls 500 Bq to 62.5 Bq in 86.4 years.