Nick bought a pair of glasses for $200. he later saw the same glasses advertised for 20% less than what he originally paid. what price were the glasses being advertised for?  

Mrs. morton has a special reward system for her class. when all her students behave well, she rewards them by putting 3 marbles into a marble jar. when the jar has 100 or more marbles, the students have a party. right now, the the jar has 24 marbles. how could mrs. morton reward the class in order for the students to have a party?

Average acceleration: i have no idea how to do this.

If sr is 4.5cm and tr is 3cm, what is the measure in degrees of angle s?