Answer:
320 g flour
8 g salt
12 g yeast
20 ml oil
Explanation:
To get from 600 to 400, divide by 1.5
To find the amounts of the other ingredients she will use, divide by 1.5
480/1.5 = 320 g flour
12/1.5 = 8 g salt
18/1.5 = 12 g yeast
30/1.5 = 20 ml oil