# High school probability questions and answers

Recent questions in High school probability

### if the probability of event A is $$\displaystyle{\frac{{{3}}}{{{4}}}}$$ and the probability of event B is 1/4 then the probability of both A and B occuring at the same time is A)1 or absolute certainty B) $$\displaystyle{\frac{{{1}}}{{{2}}}}$$ C) $$\displaystyle{\frac{{{3}}}{{{16}}}}$$ D) $$\displaystyle{\frac{{{3}}}{{{4}}}}$$ E) $$\displaystyle{\frac{{{1}}}{{{4}}}}$$

Edmund Conti 2021-11-20 Answered

### Here is the probability model for the blood type of a randomly chosed person in the United States. $\begin{array}{|c|c|} \hline Blood\ type & O&A&B&AB \\ \hline Probability&0.53&0.18&0.01&0.28\\ \hline \end{array}$ What is the probability that a randomly chosen American does not have type O blood?

Michelle Isakson 2021-11-20 Answered

### Although it’s hard to be definitive in classifying people as right- or left-handed, some studies suggest that about 14% of people are left-handed. Since $$\displaystyle{0.14}\times{0.14}={0.0196}$$ the Multiplication Rule might suggest that there’s about a 2% chance that a brother and a sister are both lefties. What’s wrong with that reasoning?

Pearl Carney 2021-11-19 Answered