Probability of Combined Events
Favourable outcome
An outcome that counts as the event you are finding the probability of.
| English | Favourable outcome |
|---|---|
| Bahasa Melayu | Hasil dikehendaki |
| 中文 | 有利结果 |
How it is used
Rolling a fair die and wanting an even number, the favourable outcomes are 2, 4 and 6, so there are 3 of them. Then P(even) = 3/6 = 1/2.
Where it shows up in SPM
The numerator in the basic probability formula P(A) = n(A)/n(S). Identifying favourable outcomes correctly is the first counting step in nearly every probability question, in Paper 1 and Paper 2.
The word 'favourable' simply means the outcomes that match the event you are asked about.
Don't confuse it with
Open the chapter: Probability of Combined Events →
Frequently asked questions
Does 'favourable' mean a good or lucky outcome?
No. It just means an outcome that counts as the event in question, even if it is 'bad' in real life.
If you are asked for P(faulty bulb), a faulty bulb is a favourable outcome for that calculation. Always match 'favourable' to whatever the question defines as the event.
How do I count favourable outcomes without missing any?
List the full sample space first, then mark every outcome that fits the event. For two dice with sum 8, systematically check pairs: (2,6),(3,5),(4,4),(5,3),(6,2), giving 5 favourable outcomes out of 36.
Working in order stops you skipping or repeating a case.