let us consider this problem:
Chelsea has a bookshelf consisting of ten classics: four Russian novels, three British novels, two French novels, and a German novel. If she wants to make sure that the novels are always grouped according to country, how many ways can she arrange the novels?
my attempt is following because these novels should be arranged according to country,it means that i should multiply number of arrangement of Russian novels together by number of British novels arrangement by French and one German Novels number of arrangement,which means that
but in answer there is $24*288=6912$ where $24$ comes from?does it means that there is $24$ ways first book i could choose? $4*3*2*1=24$?