Tree Diagrams & Combined Events
T
Tree Diagrams with Replacement and Without Replacement
Push a bit harder. Apply what you know to less familiar problems.
Mathematics · Medium
5
questions · ~4 min · 3 hints each (−5 pts)
Confidence tracking, 3-tier hints and instant feedback.
What you'll learn
Each question helps you build key knowledge and skills.
- 1When items are replaced, probabilities stay the same for each pick.
- 2When items are NOT replaced, probabilities change because the total number of items decreases.
- 3To find the probability of 'at least one', use 1 minus the probability of 'none'.
- 4Add branch probabilities together when more than one branch gives the desired outcome.
Question mix
A mix of question types to build your skills.
- Short answer×4
- True / False×1
Different question types help you think in different ways.
How it works
A simple 3-step process
- 1
Rate your confidence
Tell us how sure you feel before answering. It helps us understand your starting point.
- 2
Use hints if stuck
Get up to 3 helpful hints per question. Each hint costs 5 Treasure Points.
- 3
See what went wrong
Get instant feedback with clear explanations, so you can learn and improve.
Ready when you are
This takes about 4 minutes.

