Answer:
The ratio of blackberries to sugar is 13 : 56 or 13/56, which is already in the in the simplest form.
Explanation:
As we have to make 100g of jam
SO
Amount of strawberries = 57g
Amount of blackberries = 13g
Thus
The amount of sugar needs to be added to the mixture: 100 - (57 - 13) = 56g Therefore, the ratio of blackberries to sugar is 13:56 or 13/56, which is already in the in the simplest form.