A local DJ is given a list of then songs that he must play during his shift. Assuming that he does not repeat songs, In how many ways can the DJ arrange the first four songs that he plays during his shift?

A. 24 ways
B. 210 ways
C. 1260 ways
D. 5040 ways

Question

A local DJ is given a list of then songs that he must play during his shift. Assuming that he does not repeat songs, In how many ways can the DJ arrange the first four songs that he plays during his shift?

A. 24 ways
B. 210 ways
C. 1260 ways
D. 5040 ways

kinggeorge · Answer

He's given 10 songs. The number of ways he can order the first 4 songs is given by $$10\cdot9\cdot8\cdot7$$Since he has ten choices for the first song, 9 for the second, 8 for the third, and 7 for the fourth.