Eddie and Janice are buying school supplies. Eddie buys 5 notebooks and 6 binders for a total of $25.45. Janice buys 4 notebooks and 8 binders for $30.60. What is the cost of each item?

The pyraminx is a rubik's cube-type toy in the shape of a tetrahedron. the pyraminx shown below has edges 15\,\text{cm}15cm long and vertical height h=12.2\,\text{cm}h=12.2cm. the triangle drawn with dashed lines is a right triangle. what is the distance rr? round your answer to the nearest tenth.