Professional chefs usually measure ingredients by weight rather than by volume. A recipe calls for 2 ounces of
flour for every 3 ounces of sugar. If you are a chef and
you use 12 ounces of sugar, how many ounces of flour
should
you
use?

The answer is 8.
Reason is because if they used 12 ounces that means they multiplied the ratio 2:3 by 4 so the sugar is 12. By doing that you’d also have to multiply 2 by 4 so that the ratio stays even. So it went from 2:3 to 8:12. Sorry if that doesn’t make sense.