Howmet corporation needs $200,000 in 5 years.
find the required quarterly payment into a sinking fund if funds are invested in an account earning 10% per year compounded quarterly.

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.