solved problem #16
solved problems #15 and #16
solved problem #13
solved problem #20. Also moved factorial method to numbers.rb in tools.
Factorial call updated. Correctness checked on project_euler site"
longest_collatzChain now produce in a result the starting number as well as chain length.
Solved problem #11.
Added datafile for problem #11.
Started working on method to convert number in its words representation.
Added conversion digits to words.
Added conversion number to words up to 100
Added conversion number to words up to one thousand
Added realization for conversion number to words up to nine ninetees. It's enought to only add names for next tens powers to extend right border.
Added solution for problem #17. Not checked on site yet.
Added solution for problem #19. Not checked yet.