Answer A and B and please show work.

11. Info: 8 ounces of coffee typically contains 60-120 mg of caffeine. The amount of caffeine in your body follows the exponential decay model: A = Ace" "' . The half-life of caffeine in your body is approximately 5.7 hours. a. What is the decay constant for coffee: b. You have 200 mg of caffeine at 1:00 PM. You have trouble sleeping if your body has more than 25 mg of caffeine. How long will it take before your body is down to 25 mg caffeine