Event E is the two numbers are not even. The complement of event E is the two numbers are even. The number of outcomes of the complement of event E is 5 * 4 = 20, but since the outcome 2, 4 is the same as the outcome 4, 2, you need to divide the number of outcomes by 2.
2/5 and 1/3 have a common denominator of 15. 6/15, 5/15, and 4/15 add up to 15/15. So the chances of rock are 4/15. 120 divided by 15 is 8. Six times eight equals fourty eight, five times eight equals forty, and four times eight equals thirty two. So there are 48 classical songs, 40 jazz songs, and 32 rock songs.
