A drawer contains different types of stationery. The table gives information about the number of each item.
| Item | Pens | Pencils | Erasers | Rulers |
|---|---|---|---|---|
| Frequency | 8 | 5 | 4 | 3 |
An item is chosen at random from the drawer.
Write down the probability that the item is a ruler.
Write down the probability that the item is not a pen.
