Answer:
50 minutes
Step-by-step explanation:
she spent 1 hr and 30 minutes on homework
she spends 2/3 of an hour on the phone = 40 minutes
1 hr 30 min + 40 minutes = 2 hrs and 10 min
so she had 50 minutes to kill before bedtime since she goes to sleep 3 hrs after dinner
2hr 10 min + 50 min = 3 hrs.
