What does bc equal ?

: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?

Ade and abc are similar. which best explains why the slope of the line between points a and d is the same as the slope between points a and b?

1) prove that 731^3−631^3 is divisible by 100 2) prove that 99^3−74^3 is divisible by 25