you have some growth ratio r:
20 pounds flour make 31 pounds bread
20*r=31
r=31/20
x pounds flour make 60 pounds bread
x*r=60
x=60/r
x=60/(31/20)
x=20*60/31
or about 38.7 pounds of flour
Other ingredients:
11 pounds "other" for 31 pounds of bread
-> 11/31 per pound
-> 60*11/31 pounds of "other" for 60 pounds breads
=660/31
=21+(9/31)
