last week christi spent 2 3/4 hours playing piano this week she spent 3 2/4 hours playing piano how much more time did she play piano this week

Answer: 45 minutes

Step-by-step explanation:

On the first week she played 2 3/4 hours which translates to 2 hrs and 45 minutes (165 min), and this week she played for 3 2/4 hours which is 3 hours and 30 minutes (210 minutes)

Then just do 210 minus 165, and you'll get 45 minutes, which can also be said as 3/4 of an hour.