CPM Homework Help : ACC7 Problem 9-15

Jack has $120$ songs on his music player. Some are rock, some are jazz, and the rest are classical pieces. If his music player is on random shuffle mode, the probability that it will play a classical piece is $\frac { 2 } { 5 }$ and the probability that it will play a jazz piece is $\frac { 1 } { 3 }$ . How many songs of each type are on Jack’s music player?

Hint:

If the probability of playing a classical piece is two fifths, that means that two-fifths of the songs on Jack's music player are classical.
Can you create and solve a proportion to find out how many songs out of $120$ are classical?

Hint 2:

Your proportion might look something like this $\frac{2}{5}=\frac{r}{120}$ . Can you solve this proportion?

Answer:

Jack has $48$ classical songs on his music player. Can you find the number of jazz and rock songs on his music player?

More Help:

After you use a proportion to find how many jazz pieces Jack has, subtract the sum of classical and jazz songs from the total of $120$ to find the number of rock songs on his music player.