Probability questions in Decision Making are usually easier when you make the possible outcomes visible.
A probability tree can help with multi-stage events.
Write each outcome on a branch and place the probability beside it.
For an “and” event across a branch, you usually multiply the probabilities along that path.
If several separate outcomes satisfy the question, you may then add their probabilities.
The exact calculation matters, but structure matters first.
Another important distinction is whether events are independent or dependent. If something is removed and not replaced, the probabilities can change.
Keep fractions exact where possible. Converting too early can create unnecessary calculator work.
Always check that your final probability is sensible. It should not be negative or greater than 1.
Probability becomes much less intimidating when you stop trying to imagine everything mentally and draw the branches clearly.
