Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Likelihood refers to how likely it is that an event will happen.
We use specific words to describe chance: Impossible, Unlikely, Even Chance, Likely, and Certain.
An event is Impossible if there is no way it can happen. For example, rolling a on a standard -sided die.
An event is Unlikely if it might happen, but probably won't. For example, winning a raffle when you only have one ticket out of .
An event has an Even Chance if it is just as likely to happen as not to happen ( chance). For example, tossing a coin and getting 'Heads'.
An event is Likely if it will probably happen, but is not guaranteed. For example, picking a red marble from a bag containing red marbles and blue marble.
An event is Certain if it will definitely happen. For example, the day after Monday being Tuesday.
📐Formulae
💡Examples
Problem 1:
A bag contains green marbles and blue marbles. What is the likelihood of picking a green marble?
Solution:
The likelihood is an Even Chance.
Explanation:
Since there are an equal number of green () and blue () marbles, the total outcomes are . The probability is , which is exactly half or an even chance.
Problem 2:
If you roll a standard -sided die, what is the likelihood of rolling a number less than ?
Solution:
The likelihood is Certain.
Explanation:
A standard die has numbers and . All of these numbers are less than , so it is guaranteed to happen.
Problem 3:
What is the likelihood of it snowing in the Sahara Desert tomorrow?
Solution:
The likelihood is Unlikely (or almost Impossible).
Explanation:
While weather can be unpredictable, the Sahara Desert is extremely hot and dry, making snow a very rare event.
Problem 4:
A spinner is divided into sections: are colored Red and is colored Yellow. What is the likelihood that the spinner lands on Red?
Solution:
The likelihood is Likely.
Explanation:
Because of the spinner is Red, there is a much higher chance of landing on Red than on Yellow.