Conditional Probability & Venn Diagrams: Grade 10 Quiz

A bag contains 5 red and 3 blue marbles. If one marble is drawn at random, what is the probability that it is red given that it is not blue?

• 0.5

• 2

• 1

• 3

In a class of 30 students, 18 are girls and 12 are boys. If a student is selected at random, what is the probability that the student is a girl given that the student is not a boy?

• 1

• 0.4

• 0.6

• 0.5

A survey shows that 70% of people like chocolate and 40% like vanilla. If a person likes chocolate, what is the probability that they also like vanilla, assuming these preferences are independent?

• 0.5

• 0.3

• 0.4

• 0.7

In a deck of cards, what is the probability of drawing a heart given that the card drawn is a face card? Use a Venn diagram to illustrate your answer.

• 1/12

• 1/10

• 1/6

• 1/4

A factory produces 1000 light bulbs, of which 200 are defective. If a bulb is selected at random, what is the probability that it is defective given that it is from a batch that has a 20% defect rate?

• 0.2

• 0.5

• 0.3

• 0.1

In a school, 60% of students play soccer and 30% play basketball. If a student is chosen at random, what is the probability that they play soccer given that they do not play basketball?

• 6/7

• 4/5

• 3/10

• 1/2

A box contains 4 green and 6 yellow balls. If one ball is drawn, what is the probability that it is green given that it is not yellow?

• 1

• 3

• 2

• 0.5

In a survey, 80% of respondents own a car and 50% own a bike. If a respondent owns a car, what is the probability that they also own a bike, assuming the events are independent?

• 0.5

• 0.6

• 0.8

• 0.25

A restaurant has a 60% chance of serving vegetarian dishes and a 25% chance of serving gluten-free dishes. If a dish is vegetarian, what is the probability that it is also gluten-free?

• The probability is 15%.

• Cannot be determined without additional information.

• The probability is 25%.

• The probability is 60%.

In a group of 50 people, 30 like coffee and 20 like tea. If a person is selected at random, what is the probability that they like coffee given that they do not like tea?

• 0.25

• 1

• 0.5

• 0.75