Calculating Probabilities

If a set of events have an equal chance of occurring, it is possible to calculate probabilities.

For example, you can calculate the probability of rolling a 4 on a die because the 4 has the same chance of occurring as the other numbers.

Calculating Probabilities

If you can calculate probabilities, you can use this simple method:

The probability of an event happening

The number of results you want

The number of possible results

=

Calculating Probabilities

If you can calculate probabilities, you can use this simple method:

The probability of rolling a 4 on a normal die

1 side with the number 4

6 possible sides

=

Calculating Probabilities

If you can calculate probabilities, you can use this simple method:

The probability of rolling a 4 on a normal die

1

6=

Calculating Probabilities

Which of these statements are true about the word MATHEMATICAL?

•The probability of picking a vowel is 50 % because a letter picked is either a vowel or it isn’t.

•The probability of picking a vowel is 5

because there are 5 vowels out of 12

12 letters.

False, there are less vowels than consonants.

True

Calculating Probabilities

car

walk

bus

bike

otherHow class 6b get to school

Decide which of these statements are true.

This spinner represents all of class 6B

Calculating Probabilities

car

walk

bus

bike

other

The chance of landing on a person who said bike or car is the same as landing on a person who walks.

The chance of getting “bike” is the same as getting “car”

True

False

Calculating Probabilities

car

walk

bus

bike

other

The chance of getting “car” is 1

2

The chance of getting car is 25 %

False

True