Alejandro has three ladders that are 15,10, and 12 feet in length . if he trying to reach a window that is 8 feet from the ground then

Ateacher wanted to buy a chair, a bookshelf, two tables and a desk. she spent $900 for all five items and the chair and the desk combined 70% of her total. if the bookshelf cost $50, how much did each of the tables cost?