A rate is a ratio involving quantities, typically with different units.
A rate where the second quantity is 1 is called a unit rate.
The ratio is pound of butter per cups of flour.
To find the amount of butter per 1 cup of flour, or the unit rate, divide pound of butter by cups of flour.
Use the improper fraction in place of the mixed number .
So, pound of butter is needed for 1 cup of flour.