The video tutorial explains how to calculate the theoretical probability of selecting a blue or red pen from a collection of pens. It begins by identifying the total number of pens and the possible outcomes. The instructor then demonstrates how to calculate the probability of picking a blue or red pen by adding the number of blue and red pens and dividing by the total number of pens. The result is converted into a percentage and rounded to the nearest whole number. The tutorial concludes with a summary of the process for finding the total number of equally likely outcomes.

How many total pens are there in the collection?

• 85

• 100

• 90

• 80

What is the probability of picking a blue or red pen?

• 55/90

• 35/90

• 40/90

• 15/90

What does the term 'inclusive or' mean in probability?

• Both events must occur

• Either or both events can occur

• Only one event can occur

• Neither event can occur

What is the percentage probability of picking a blue or red pen?

• 61%

• 62%

• 60%

• 63%

How do you calculate the percentage from a probability fraction?

• Multiply by 100

• Divide by 100

• Add 100

• Subtract 100