Answer:
2/3 of an hour
Explanation:
Since Ivan has 4 total hours of music on his mp3, you can multiply the number of hours by the fraction of time:
![4*(1)/(6)=(4)/(1)*(1)/(6)=(4)/(6)=(2)/(3)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/p4swpwt03pb2p8okk7bpqbl5z4dg2sppuw.png)
Given that Jazz makes up 1/6 of the total, than only 2/3 of an hour on Ivan's mp3 player would be Jazz.