This is a question on combinations.
Combinations are applied to find the number of unique outcomes that are obtainable.
To select r from a sample space of n, the number of ways that r can selected from n is given as:
[tex]^nC_r[/tex]In this case,
n = number of total songs
r = number of songs chosen at one time.
Therefore, the number of ways that 3 rock songs can be chosen from 8 is given as:
[tex]^8C_3=\frac{8!}{(8-3)!3!}=\frac{8!}{5!3!}=\frac{8\times7\times6\times5!}{5!\times3!}=56[/tex]The number of ways that 4 alternative songs can be chosen from 5 is given as:
[tex]^5C_4=\frac{5!}{(5-4)!4!}=\frac{5!}{1!4!}=\frac{5\times4!}{4!\times1!}=5[/tex]The number of ways that 3 rap songs can be chosen from 6 is given as:
[tex]^6C_3=\frac{6!}{(6-3)!3!}=\frac{6!}{3!3!}=\frac{6\times5\times4\times3!}{3!\times3!}=20[/tex]Therefore, The total number of ways that Steve can select his songs is:
[tex]56\times5\times20=5600\text{ ways}[/tex]