The given probability is 1/5.
We know that the odd is the ratio of the favorable outcomes to non-favorable outcomes.
Let P=1/5 be the probability of the event occurring
Then 1-P is the probability of the event not occurring
[tex]1-P=1-\frac{1}{5}=\frac{5}{5}-\frac{1}{5}=\frac{5-1}{5}=\frac{4}{5}[/tex]The probability of the event not occurring is 4/5
The ratio is
[tex]\frac{\frac{1}{5}}{\frac{4}{5}}=\frac{1}{5}\times\frac{5}{4}=\frac{1}{4}[/tex]The odd of the given probability is
[tex]1\colon4[/tex]