topic badge
iGCSE (2021 Edition)

23.09 Conditional probability (Extended)

Interactive practice questions

A student creates the following diagram of their favourite animals.

a

How many of the animals have four legs?

b

How many of the animals have four legs and stripes?

c

What is the probability of selecting an animal with stripes given that it has four legs?

Easy
1min

The following are probabilities for an experiment in which $A$A and $B$B are two possible events.

$P\left(A\cap B\right)=0.48$P(AB)=0.48, and

$P\left(A\right)=0.6$P(A)=0.6.

Find $P\left(B|A\right)$P(B|A).

Easy
1min

For events $A$A and $B$B we can find the probability of $A$A given $B$B using$P\left(A|B\right)=\frac{P\left(A\cap B\right)}{P\left(B\right)}$P(A|B)=P(AB)P(B).

Easy
1min

Oliver watches three episodes of TV each night.

He begins with News ($N$N) or Current Affairs ($C$C), then the next two shows are either Horror ($H$H) or Animation ($A$A).

He never watches more than one Horror show, and if he watched the News, he will follow this immediately with an Animation.

At every stage, the possible outcomes of each choice are equally likely,

Easy
3min
Sign up to access Practice Questions
Get full access to our content with a Mathspace account

Outcomes

0580E8.6

Calculate conditional probability using Venn diagrams, tree diagrams and tables.

What is Mathspace

About Mathspace