In which graph does y vary directly as x?
A) A
B) B
C) C
D) D

Compare the subtraction problems 6/8 - 5/8 = 1/8 and 6/9 - 7/9 = 1/9 why is the answer to the first problem positive and the answer to the second problem negative

:24% of students in a class are girls. if there are less than 30 students in this class, how many students are there? how many girls are there?

Last month, a 770 g box of cereal was sold at a grocery store for $3.10. however, this month, the cereal manufacturer launched the same cereal in a 640 g box, which is being sold at $2.50. what is the percent change in the unit price?