To find the probability of picking an even number from the list {2, 4, 5, 7, 9, 10, 12, 15, 18, 20}, we first need to identify how many of the numbers in the list are even.
The even numbers in the list are:
- 2
- 4
- 10
- 12
- 18
- 20
This gives us a total of 6 even numbers.
The total number of numbers in the list is 10.
The probability \( P \) of picking an even number is given by the ratio of the number of even numbers to the total number of numbers:
\[ P(\text{even}) = \frac{\text{Number of even numbers}}{\text{Total numbers}} = \frac{6}{10} \]
Now, we need to simplify \( \frac{6}{10} \):
\[ \frac{6}{10} = \frac{3}{5} \]
Thus, the probability of getting an even number is \( \frac{3}{5} \).