Without overlapping, what is the maximum number of 2×4 rectangles that can be drawn on a 6×10 grid ?

65% of students in your school participate in at least one after school activity. if there are 980 students in you school, how many do not participate in an after school activity?

What is the lcm of 16 and 40 ? 24 and 40 ?

He mass of a single atom of carbon can be found by dividing the atomic mass (12.01 g) by 6.022 x 10^23. which is the mass of a single carbon atom, correctly written in scientific notation with the correct number of significant figures?