Why keyboard letters are randomnly placed?

The QWERTY keyboard is not random. It was designed by Christopher Sholes in in the early 1870's. He was trying to design a type writer that didn't jam up with rapid succession of the type bars moving (a fast typist). After trial and error for several years, Sholes eventually developed the QWERTY keyboard that had the lowest rate of jamming of all designs he tried. For more information, search Wikipedia for QWERTY. Thank you.