Answer: 3 cups are actually needed for the recipe.
Step-by-step explanation: The chef has a recipe that calls for 4 cups of flour. And she wants to make 3/4 of the recipe. Which mathematically means she multiplies all the quantities of ingredients each by 3/4; and for flour, it is (3/4) × 4 = 3 cups. And she could have just taken 3 cups.
But she goes ahead and takes 3/4 of a cup, 4 times, that is, (3/4) + (3/4) + (3/4) + (3/4) = 3 cups. Still equal to 3 cups.
This works because, simple problems like this are multiple solution problems.