Question

63% of students at one college drink coffee, and 16% of people who drink coffee suffer from insomnia. What is the probability that a randomly selected student drinks coffee and suffers from insomnia?

Answer 1

It is given that, yet 63% students drink coffee, 16% among those 63% percent are the one suffereing from insomnia. Supposing that there are total n students in the college, there will be students who drink coffee. Among 16% of the , or are the one who suffer insomnia.

Hence, the probability that a randomly selected student drinks coffee and suffer from insomnia would be or 10.08%.

Note: This solution must not be confused with or taken anlogous to the probability rule that , which is quite different. We must consider the problem with the conditional probability. Supposing A is the people who drinks coffee and hence while B is the people who suffers from insomnia and hence (ie probability that B given A is 0.16). Hence, 's probability would be found as or or .