A bag contains 120 marbles. Some are red and the rest are black. There are 19 red marbles for every black marble. How many black marbles are there?

Solve for n? [tex]z = \frac{3}{4} mn[/tex]

The rectangle shown has a perimeter of 108 cm and the given area. its length is 6 more than five times its width. write and solve a system of equations to find the dimensions of the rectangle.

Madeline takes her family on a boat ride. going through york canal, she drives 6 miles in 10 minutes. later on as she crosses stover lake, she drives 30 minutes at the same average speed. which statement about the distances is true?