Pick a counter — simple probability
A simple probability question about picking a counter from a bag of three colours.
The Question
A bag holds 4 red, 5 blue and 3 green counters. One counter is taken out. What is the probability that it is blue? What is the probability that it is not green?
The Answer
Reveal the Answer
12 counters altogether, so every probability is out of 12. Blue: 5/12. Not green means red or blue, 4 + 5 = 9, so 9/12 = 3/4. The check: P(green) + P(not green) = 3/12 + 9/12 = 1.
Now watch the solution
Practice Sheet + Marked Answers
The four-question practice sheet, the solutions in our teaching voice and a self-marking quiz for this question are part of The Question Desk course — every school day of the term, with progress you can see. Enrolled group students get it included.
Want a Plan Built Around Your Child, Not Just This Week’s Question?
Small groups of around 4–5 (max 8), matched to your child’s year group and pace. Start with the free baseline assessment and we’ll tell you exactly where they are.
