Unit rate is a rate that has a denominator of 1. In order to get the unit rate given the denominator is not 1, then unit rate is acquired by getting the equal ration with denominator 1. On the question, Letter A. 4 yd/carry, Letter B. 35 mi/1gal and Letter D. 3 cups per batch are unit rates.
The answer would be $1152 because you need to multiply 1440 by .2 because it’s 20% and then you need to subtract whatever you got by 1440. And you’ll get the answer 1152