To solve this problem, follow these steps:
1. Determine the Total Number of Cards:
We have 20 cards numbered from 1 to 20.
2. Identify Cards Containing the Digit '1':
We need to find out how many of these cards have the digit '1' in their number.
- The cards with a '1' are: 1, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19.
- Counting these, we have 11 cards that contain the digit '1'.
3. Calculate the Number of Cards Without the Digit '1':
- Total cards: 20
- Cards with '1': 11
- Cards without '1': 20 - 11 = 9
4. Calculate the Probability:
The probability that a randomly chosen card does not have the digit '1' is the ratio of the number of cards without '1' to the total number of cards.
- Number of cards without '1': 9
- Total number of cards: 20
Therefore, the probability is [tex]\( \frac{9}{20} \)[/tex].
5. Convert the Probability to Decimal Form:
[tex]\( \frac{9}{20} = 0.45 \)[/tex]
Thus, the probability that a randomly chosen card does not have the digit '1' in its number is 0.45.
