Hi all,(adsbygoogle = window.adsbygoogle || []).push({});

I think this would be a probability question.

We do a random check. 10% smokes marihuana. This test gives the right results in only 90%. One person is tested positive. How big is the chance that he really smoked marihuana?

-if there are 8 people in total.

-is it also possible to make an assumption if the size of the group is not known?

thanks a lot!

Martine

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

Dismiss Notice

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!

# Probability question

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