You have a deck of 20 cards numbered from 1 to 20.
If you draw a card at random, the set of possible outcomes is:
[tex]\mleft\lbrace1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20\mright\rbrace[/tex]Let "A" represent the event "draw a card at random and it has a number less than 9"
The possible outcomes from the deck that fulfill the condition stated for A are all cards with numbers less than 9:
[tex]A=\mleft\lbrace1,2,3,4,5,6,7,8\mright\rbrace[/tex]So out of the 20 cards, there are 8 cards with a number "less than 9"
The probability of drawing a card with a number less than 9 can be determined as the quotient between the favourable outcomes and the total number of outcomes:
Favorable outcomes: 8
Total outcomes: 20
[tex]\begin{gathered} P(A)=\frac{8}{20}=\frac{2}{5} \\ P(A)=0.4 \end{gathered}[/tex]The probability that a card is chosen at random has a number less than 9 is 0.4