Answer: The required number of cups needed is 0.75.
Step-by-step explanation: Given that we need [tex]1\dfrac{1}{4}[/tex] cups of sugar to make 20 cookies.
We are to find the number of cups of sugar needed to make 12 cookies.
We will be using the UNITARY method to solve the problem.
We have
Number of cups of sugar needed to make 20 cookies is
[tex]1\dfrac{1}{4}=\dfrac{5}{4}.[/tex]
So, the number of cups of sugar needed to make 1 cookie is
[tex]\dfrac{5}{4}\times\dfrac{1}{20}=\dfrac{1}{16}.[/tex]
Therefore, the number of cups of sugar needed to make 12 cookies is given by
[tex]\dfrac{1}{16}\times12=\dfrac{3}{4}=0.75.[/tex]
Thus, the required number of cups needed is 0.75.
