I'm having trouble with this question.(adsbygoogle = window.adsbygoogle || []).push({});

The percent "P", of caffeine remaining in your bloodstream is related to the elapsed time, "t', in hours, by t = 5(log P/ log 0.5)

a) How long will it take for the amount of caffeine to drop to 25% of the amount consumed?

b) Suppose you drink a cup of coffee after dinner at 5:00 pm. What % of the caffeine will remain in your system when you go to bed at 10:30 pm.

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Log application question

**Physics Forums | Science Articles, Homework Help, Discussion**