GCSE Secondary Maths Age 13-17 - Probability & Statistics: Probability - Explained

The video tutorial explains a probability problem involving colored counters in a bag. It covers calculating the probability of selecting a red counter by ensuring all probabilities sum to one. It also demonstrates how to calculate the number of green counters using multiplication. The tutorial emphasizes the importance of practicing such standard probability questions, which frequently appear in GCSE exams.

What is the probability of selecting a blue counter from the bag?

• 0.05

• 0.2

• 0.25

• 0.5

If the probability of selecting a yellow counter is 0.25, what is the missing probability for the red counter?

• 0.15

• 0.2

• 0.05

• 0.1

How many counters are there in total in the bag?

• 100

• 120

• 150

• 200

What is the probability of selecting a green counter from the bag?

• 0.2

• 0.25

• 0.5

• 0.05

How many green counters are there in the bag?

• 20

• 18

• 24

• 30