The activity of a source falls from 800 Bq to 100 Bq. If its half-life is 6 hours, how long did this take?

1. A Option A: 24 hours
2. B Option B: 48 hours
3. C Option C: 18 hours
4. D Option D: 8 hours

Answer checked 11 October 2026 · How we write and check questions