If an 8000Bq source of activity has a half life of 6 days, How much activity will it have after 18 days. I know the answer is 1000Bq but could you explain how you got it very clearly?

2nd question. Calculate the half life of a source that decreases in activity from 32kBq to 8kBq in 24 days. Could you explain that clearly too? Thanks.

Asked Adam