Answer:
80g
Step-by-step explanation:
Here's why:
SO you have 2:3 ratio which means the ratio for grams of butter/grams of flour has to be 2:3.
So we set up the following equation:
2/3 = 640/x (solve for x)
x= 960g
960g is what you should have to get to ratio, but the question is asking how much more you need from the initial given flour.
So you need (suppose x is the grams of flour you need)
x+880g = 960g (solve for x)
x=80g