# Probability Concepts

## Mathematics, Grade 5

1
/
2
On which color is the spinner more likely to land? The probability of an event shows the chance that some event will occur. An event is all the possible outcomes. An impossible event has a probability of zero. A certain event has a probability of 1. Finding Probabilities You can determine the probability of an event by comparing the number of favorable outcomes with the total number of possible outcomes. There’s an even chance that the spinner will land on a green or yellow section. It is more likely that the spinner will land on a green section; and less likely that it will land on a yellow section. It is certain that the spinner will land on a green section; and impossible that it will land on a yellow section. When we toss a number cube, there are 6 possible different outcomes. It can show either 1, 2, 3, 4, 5 or 6. What is the probability that you will pick a red ball? probability of an event = number of favorable outcomes number of possible outcomes Count the number of red balls. Step 1 Count the total number of balls. Step 2 Write a fraction. Step 3 probability of picking a red ball = 1 3 1 2 probability of picking a red ball = = = 1 3 4 12 number of red balls total number of balls probability of picking a red ball = = 1 3 4 12 probability of picking a green ball = = 1 3 4 12 probability of picking a red & a green ball + = = 2 3 1 3 1 3 If you pick 2 balls from the bag, what is the probability that they will be red and green? Predicting Outcomes © Copyright NewPath Learning. All Rights Reserved. 93-4508 www.newpathlearning.com Probability Concepts
\|xiBAHBDy01660rzu On which color is the spinner more likely to land? The probability of an event shows the chance that some event will occur. An event is all the possible . An impossible event has a probability of . A certain event has a probability of . Finding Probabilities You can determine the probability of an event by comparing the number of favorable outcomes with the total number of possible outcomes. There’s an that the spinner will land on a green or yellow section. It is that the spinner will land on a green section; and that it will land on a yellow section. It is that the spinner will land on a green section; and that it will land on a yellow section. When we toss a number cube, there are 6 possible different outcomes. It can show either 1 , 2 , 3 , 4 , 5 or 6 . What is the probability that you will pick a red ball? probability of an event = number of favorable outcomes number of possible outcomes Count the number of red balls. Step 1 Count the total number of balls. Step 2 Write a fraction. Step 3 probability of picking a red ball = = probability of picking a green ball = = probability of picking a red & a green ball + = = If you pick 2 balls from the bag, what is the probability that they will be red and green? Predicting Outcomes probability of picking a red ball = probability of picking a red ball = = = number of red balls total number of balls © Copyright NewPath Learning. All Rights Reserved. 93-4508 www.newpathlearning.com Probability Concepts Key Vocabulary Terms certain chance even chance event favorable outcome impossible less likely more likely possible outcome probability