trey went to the batting cages to practice hitting. he rented a helmet for $4 and paid $0.75 for each group of 20 pitches. if he spent a total of $7 at the batting cages, how many group of pitches did he pay ?
First subtract 4 from 7 since they are just asking for the amount he paid for pitches. Then, take the difference (3) and divide it by .75 to get your answer (4 groups).