In a stationery drawer there are only pens, pencils and rulers.
number of pens : number of pencils : number of rulers=3:7:5 \text{number of pens : number of pencils : number of rulers} = 3 : 7 : 5 number of pens : number of pencils : number of rulers=3:7:5An item is taken at random from the drawer.
Complete the table to show the probabilities of the item being a pen, a pencil or a ruler.
| Item | Pen | Pencil | Ruler |
|---|---|---|---|
| Probability |
