The purity of gold alloys is traditionally measured in carats, where:
An artisan manufacturer produces high-end luxury pen nibs, X and Y, which are made from an alloy of gold and silver only.
Table 1 shows information about these pen nibs.
| Gold item | Carat | Mass of gold in grams | Mass of silver in grams |
|---|---|---|---|
| Nib X | ? | 10 | 14 |
| Nib Y | 18 | 15 | ? |
Complete Table 1 by finding the missing values represented by the question marks.