(a) Beethoven wrote 9 symphonies and Mozart wrote 27 piano concertos. If a university radio, station announcer wishes to play first a Beethoven symphony and then a Mozart concerto, in how many ways can this be done?
(b) The station manager decides that on each successive night $(7$ days per week), a Beethoven symphony will be played, followed by a Mozart piano concerto, followed by a Schubert string quartet (of which there are $15 ) .$ For roughly how many years could this policy be continued before exactly the same program would have to be repeated?