This Problem Set is a part of the Lesson 3, Unit 8, Grade 7. Understand that a numerical value (or probability) can be used to describe the chance that some event will occur. Find the probabilities of events based on the number of outcomes in the event and the size of the sample space. Learning targets: students can use the sample space to calculate the probability of an event when all outcomes are equally likely and write out the sample space for a simple chance experiment.