Your father will require 14.6 cups of sugar for the larger group
<h3>Ratio and proportions</h3>
From the question, we have that 2.5 cups of sugar can be used to make recipes for 6 people that is;
6 people = 2.5 cups of sugar
In order to calculate for 35 people, we will have;
35 people = x
Taking the ratio of the expressions
6/35 = 2.5/x
6x = 87.5
x = 87.5/6
x = 14.6
Hence your father will require 14.6 cups of sugar for the larger group
Learn more on ratio and proportions here: brainly.com/question/19994681