Answer: 2 1/4 more flour for 9 servings
Step-by-step explanation: (a) how many total cups of flour are there per serving? show your work
1 1/2÷6= 3/2 x 1/6 = 3/12= 1/4 cups of flour per serving
(b) how many total cups of sugar (white and brown) are there per serving?show your work
3/4 + 1/3 = 9/12 + 4/12= 13/12= 1 1/12 total cups of sugar
13/12 ÷ 6/1 = 13/12 x1/6 = 13/72 per serving
(c) supposed you modify the recipe so that it makes 9 servings. How much more flour do you need for the modified recipe than you need for the original recipe?Show your work/
1/4 x 9 = 9/4 = 2 1/4 more flour for 9 servings.
Step-by-step explanation:

0.99999696 is your answer I am pretty sure.
= 2025
When you are told to find the smallest length possible, you perform L.C.M(Least common multiples)
For this, you divide the given lengths using the numbers that divides all through.
I have added an image to this answer. Go through it for more explanation