Sarah is picking out some movies to rent , and she is primarily interested in comedies and horror films . she has narrowed down her selections to 19 comedies and 14 horror films.
how many different combinations of 4 movies can she rent ?
we have
total selections=19+14=33 selections
Find out the combination
n=33 and r=4
[tex]33C4=\frac{33!}{4!(33-4)!}[/tex][tex]33C4=\frac{33!}{4!(29)!}=\frac{33\cdot32\cdot31\cdot30}{4\cdot3\cdot2\cdot1}[/tex]33C4=40,920 combinations
