in 6th grade lilly read 15 books. this year in the 7th grade she read 18 books. what is the percent of increase in the number books that lilly read this year.
3% i think? because in 6th grade she read 15 books and in the 7th she read 18 books and then i subtracted 18 from 15 and got 3%.... but i could be everyworng