Mathematics for IGCSE & O level - Probability (Section 5 - No. 43)
If the odds of a certain event occurring are 4:1, what is the probability of that event occurring?
1/5
4/5
1/4
5/4
Explication
Odds of 4:1 mean 4 favorable to 1 unfavorable. So probability is 4/(4+1) = 4/5.