Probability — Quiz 1

Questions in this quiz (9)

1. A lunch counter offers customers three sandwich options: turkey, ham, and veggie. There are 5 drink choices: water, soda, juice, tea, or milk. What is the probability that a customer who randomly selects a sandwich and a drink chooses soda after having selected the ham sandwich?

   • $$\frac{2}{5}$$
   • $$\frac{1}{8}$$
   • $$\frac{1}{4}$$
   • $$\frac{1}{5}$$

2. A survey asked 120 visitors at a zoo how long they spent during their visit. The table below shows the responses grouped by visitor type and time spent. What is the probability that a visitor spent more than 2 hours at the zoo, given that the visitor was an adult?

   • $$\frac{1}{6}$$
   • $$\frac{2}{7}$$
   • $$\frac{1}{5}$$
   • $$\frac{5}{12}$$

3. In a movie theater, there are 32 people who bought popcorn, 25 who bought a drink, and 12 people who bought popcorn and a drink. What is the probability that a randomly selected person who bought popcorn also bought a drink?

   • $$\frac{3}{8}$$
   • $$\frac{12}{25}$$
   • $$\frac{1}{8}$$
   • $$\frac{5}{8}$$

4. At a music festival, the organizer plays one of five types of music at random: Jazz, Classical, Hip Hop, Country, and Blues. If each type of music is equally likely to be chosen, what is the probability that the next two songs played will be a Jazz song followed by a Country song?

   • $$\frac{2}{5}$$
   • $$\frac{2}{25}$$
   • $$\frac{24}{25}$$
   • $$\frac{1}{25}$$

5. At a coffee shop, 40 customers bought a muffin, 30 bought a coffee, and 18 bought both a muffin and a coffee.What is the probability that a randomly selected customer who bought a muffin also bought a coffee?

   • $$\frac{3}{5}$$
   • $$\frac{3}{4}$$
   • $$\frac{9}{20}$$
   • $$\frac{9}{11}$$

6. During a lab test, two independent machines analyze samples. Machine X produces correct results $$\frac{4}{5}$$ of the time. Machine Y produces correct results $$\frac{2}{3}$$ of the time. Assuming the machines work independently, what is the probability that both Machine X and Machine Y produce correct results on a given test?

   • $$\frac{8}{15}$$
   • $$\frac{2}{15}$$
   • $$\frac{13}{15}$$
   • $$\frac{7}{15}$$

7. A die is rolled once. What is the probability of rolling an even number?

   • $$\frac{1}{2}$$
   • $$\frac{1}{6}$$
   • $$\frac{2}{3}$$
   • $$\frac{1}{3}$$

8. What is the sum of the probabilities of all possible outcomes of a coin toss?

   • $$\frac{1}{6}$$
   • $$1$$
   • $$\frac{1}{2}$$
   • $$\frac{1}{3}$$

9. A class has 20 boys and 30 girls. If one student is chosen at random, what is the probability it's a girl?

   • $$\frac{2}{5}$$
   • $$\frac{3}{5}$$
   • $$\frac{1}{30}$$
   • $$\frac{2}{3}$$