Answer:
16-20 Hours
Explanation:
Knowing each day she practices 4-5 hours, to find how much she practices each day we multiply the hours played per day (4) by the lowest possible hours(4) played and highest(5) possible hours played to get the minimum and maximum possibilities.
To find minimum hours played per week:

To find minimum hours played per week

Then we know she must play between 16 and 20 hours per week.