## anonymous 5 years ago 0.82 = 1e^(3k) How do I solve for K?

1. anonymous

Take ln for both sides and you're almost done.

2. anonymous

Not quite good with these, as we still didn't study logarithms in school. But I think $\ln$ will help solve the thing.

3. anonymous

This is right Moe.

4. anonymous

Thanks mate. I'll be taking Maths Level 2 Sunject Test in a month, so I'll get to use logarthims quite a bit :)

5. anonymous

Good Luck! :)

6. anonymous

@remidia, did you get the idea here?

7. anonymous

No, this whole problem is really confusing me. The problem in its entirety is The amount of a drug in a person's bloodstream can be modeled with exponential decay. Suppose that, in 3 hours, 18% of the drug is removed from the bloodstream. What is the half-life of the drug? A) 8.1 hours B) 8.7 hours C) 9.3 hours D) 9.9 hours E) 10.5 hours